From 2485428fe0e199af2d7bb01a0528b7d8e9535ff4 Mon Sep 17 00:00:00 2001
From: Alexa <alexa@nanako.hinata.org>
Date: Thu, 28 Oct 2021 00:51:56 -0600
Subject: [PATCH 01/23] Initial work on Fossil resolver

---
 src/config.cr           |   1 +
 src/resolvers/fossil.cr | 447 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 448 insertions(+)
 create mode 100644 src/resolvers/fossil.cr

diff --git a/src/config.cr b/src/config.cr
index 51802006..8ee8db28 100644
--- a/src/config.cr
+++ b/src/config.cr
@@ -13,6 +13,7 @@ module Shards
   VERSION_TAG           = /^v(\d+[-.][-.a-zA-Z\d]+)$/
   VERSION_AT_GIT_COMMIT = /^(\d+[-.][-.a-zA-Z\d]+)\+git\.commit\.([0-9a-f]+)$/
   VERSION_AT_HG_COMMIT  = /^(\d+[-.][-.a-zA-Z\d]+)\+hg\.commit\.([0-9a-f]+)$/
+  VERSION_AT_FOSSIL_COMMIT = /^(\d+[-.][-.a-zA-Z\d]+)\+fossil\.commit\.([0-9a-f]+)$/
 
   def self.cache_path
     @@cache_path ||= find_or_create_cache_path
diff --git a/src/resolvers/fossil.cr b/src/resolvers/fossil.cr
new file mode 100644
index 00000000..b208aed2
--- /dev/null
+++ b/src/resolvers/fossil.cr
@@ -0,0 +1,447 @@
+require "uri"
+require "./resolver"
+require "../versions"
+require "../logger"
+require "../helpers"
+
+module Shards
+  abstract struct FossilRef < Ref
+    def full_info
+      to_s
+    end
+  end
+
+  struct FossilBranchRef < FossilRef
+    def initialize(@branch : String)
+    end
+
+    def to_fossil_ref
+      @branch
+    end
+
+    def to_s(io)
+      io << "branch " << @branch
+    end
+
+    def to_yaml(yaml)
+      yaml.scalar "branch"
+      yaml.scalar @branch
+    end
+  end
+
+  struct FossilTagRef < FossilRef
+    def initialize(@tag : String)
+    end
+
+    def to_fossil_ref
+      @tag
+    end
+
+    def to_s(io)
+      io << "tag " << @tag
+    end
+
+    def to_yaml(yaml)
+      yaml.scalar "tag"
+      yaml.scalar @tag
+    end
+  end
+
+  struct FossilCommitRef < FossilRef
+    getter commit : String
+
+    def initialize(@commit : String)
+    end
+
+    def =~(other : FossilCommitRef)
+      commit.starts_with?(other.commit) || other.commit.starts_with?(commit)
+    end
+
+    def to_fossil_ref
+      @commit
+    end
+
+    def to_s(io)
+      io << "commit " << @commit[0...7]
+    end
+
+    def full_info
+      "commit #{@commit}"
+    end
+
+    def to_yaml(yaml)
+      yaml.scalar "commit"
+      yaml.scalar @commit
+    end
+  end
+
+  struct FossilTipRef < FossilRef
+    def to_fossil_ref
+      "tip"
+    end
+
+    def to_s(io)
+      io << "tip"
+    end
+
+    def to_yaml(yaml)
+      raise NotImplementedError.new("FossilTipRef is for internal use only")
+    end
+  end
+
+  class FossilResolver < Resolver
+    @@has_fossil_command : Bool?
+    @@fossil_version : String?
+
+    @origin_url : String?
+    @local_fossil_file : String?
+
+    def self.key
+      "fossil"
+    end
+
+    def self.normalize_key_source(key : String, source : String) : {String, String}
+      case key
+      when "fossil"
+        {"fossil", source}
+      else
+        raise "Unknown resolver #{key}"
+      end
+    end
+
+    protected def self.has_fossil_command?
+      if @@has_fossil_command.nil?
+        @@has_fossil_command = (Process.run("fossil version", shell: true).success? rescue false)
+      end
+      @@has_fossil_command
+    end
+
+    protected def self.fossil_version
+      @@fossil_version ||= `fossil version`[/version\s+([^\s]*)/, 1]
+    end
+
+    def read_spec(version : Version) : String?
+      update_local_cache
+      ref = fossil_ref(version)
+
+      if file_exists?(ref, SPEC_FILENAME)
+        capture("fossil cat -R #{Process.quote(local_fossil_file)} #{Process.quote(SPEC_FILENAME)} -r #{Process.quote(ref.to_fossil_ref)}")
+      else
+        Log.debug { "Missing \"#{SPEC_FILENAME}\" for #{name.inspect} at #{ref}" }
+        nil
+      end
+    end
+
+    private def spec_at_ref(ref : FossilRef, commit) : Spec
+      update_local_cache
+
+      unless file_exists?(ref, SPEC_FILENAME)
+        raise Error.new "No #{SPEC_FILENAME} was found for shard #{name.inspect} at commit #{commit}"
+      end
+
+      spec_yaml = capture("fossil cat -R #{Process.quote(local_fossil_file)} #{Process.quote(SPEC_FILENAME)} -r #{Process.quote(ref.to_fossil_ref)}")
+      begin
+        Spec.from_yaml(spec_yaml)
+      rescue error : Error
+        raise Error.new "Invalid #{SPEC_FILENAME} for shard #{name.inspect} at commit #{commit}: #{error.message}"
+      end
+    end
+
+    private def spec?(version)
+      spec(version)
+    rescue Error
+    end
+
+    def available_releases : Array(Version)
+      update_local_cache
+      versions_from_tags
+    end
+
+    def latest_version_for_ref(ref : FossilRef?) : Version
+      update_local_cache
+      ref ||= FossilTipRef.new
+      begin
+        commit = commit_sha1_at(ref)
+      rescue Error
+        raise Error.new "Could not find #{ref.full_info} for shard #{name.inspect} in the repository #{source}"
+      end
+
+      spec = spec_at_ref(ref, commit)
+      Version.new "#{spec.version.value}+fossil.commit.#{commit}"
+    end
+
+    def matches_ref?(ref : FossilRef, version : Version)
+      case ref
+      when FossilCommitRef
+        ref =~ fossil_ref(version)
+      when FossilBranchRef, FossilTipRef
+        # TODO: check if version is the branch
+        version.has_metadata?
+      else
+        # TODO: check branch and tags
+        true
+      end
+    end
+
+    protected def versions_from_tags
+      capture("fossil tag list -R #{Process.quote(local_fossil_file)}")
+        .split('\n')
+        .compact_map { |tag| Version.new($1) if tag =~ VERSION_TAG }
+    end
+
+    def install_sources(version : Version, install_path : String)
+      update_local_cache
+      ref = fossil_ref(version)
+
+      FileUtils.rm_r(install_path) if File.exists?(install_path)
+      Dir.mkdir_p(install_path)
+      Log.debug { "Local path: #{local_path}" }
+      Log.debug { "Install path: #{install_path}" }
+
+      install_fossil_file = Path[install_path].join("..", "#{name}.fossil").normalize.to_s
+      #run "fossil clone #{Process.quote(local_fossil_file)} #{install_fossil_file}"
+      run "fossil open #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)} --workdir #{install_path}"
+    end
+
+    def commit_sha1_at(ref : FossilRef)
+      capture("fossil timeline #{Process.quote(ref.to_fossil_ref)} -t ci -n 1 -F %H -R #{Process.quote(local_fossil_file)}").strip.lines[0]
+    end
+
+    def local_path
+      @local_path ||= begin
+                        uri = parse_uri(fossil_url)
+
+                        path = uri.path
+                        path = Path[path]
+                        # E.g. turns "c:\local\path.git" into "c\local\path.git". Or just drops the leading slash.
+                        if (anchor = path.anchor)
+                          path = Path[path.drive.to_s.rchop(":"), path.relative_to(anchor)]
+                        end
+
+                        if host = uri.host
+                          File.join(Shards.cache_path, host, path)
+                        else
+                          File.join(Shards.cache_path, path)
+                        end
+                      end
+    end
+
+    def local_fossil_file
+      @local_fossil_file ||= Path[local_path].join("..", "#{name}.fossil").normalize.to_s
+    end
+
+    def fossil_url
+      source.strip
+    end
+
+    def parse_requirement(params : Hash(String, String)) : Requirement
+      params.each do |key, value|
+        case key
+        when "branch"
+          return FossilBranchRef.new value
+        when "tag"
+          return FossilTagRef.new value
+        when "commit"
+          return FossilCommitRef.new value
+        else
+        end
+      end
+
+      super
+    end
+
+    record FossilVersion, value : String, commit : String? = nil
+
+    private def parse_fossil_version(version : Version) : FossilVersion
+      case version.value
+      when VERSION_REFERENCE
+        FossilVersion.new version.value
+      when VERSION_AT_FOSSIL_COMMIT
+        FossilVersion.new $1, $2
+      else
+        raise Error.new("Invalid version for fossil resolver: #{version}")
+      end
+    end
+
+    private def fossil_ref(version : Version) : FossilRef
+      fossil_version = parse_fossil_version(version)
+      if commit = fossil_version.commit
+        FossilCommitRef.new commit
+      else
+        FossilTagRef.new "v#{fossil_version.value}"
+      end
+    end
+
+    private def update_local_cache
+      if cloned_repository? && origin_changed?
+        delete_repository
+        @updated_cache = false
+      end
+
+      return if Shards.local? || @updated_cache
+      Log.info { "Fetching #{fossil_url}" }
+
+      if cloned_repository?
+        # repositories cloned with shards v0.8.0 won't fetch any new remote
+        # refs; we must delete them and clone again!
+        if valid_repository?
+          fetch_repository
+        else
+          delete_repository
+          mirror_repository
+        end
+      else
+        mirror_repository
+      end
+
+      @updated_cache = true
+    end
+
+    private def mirror_repository
+      path = local_path
+      FileUtils.rm_r(path) if File.exists?(path)
+      Dir.mkdir_p(path)
+
+      source = fossil_url
+      # Remove a "file://" from the beginning, otherwise the path might be invalid
+      # on Windows.
+      source = source.lchop("file://")
+
+      Log.debug { "Local path: #{local_path}" }
+      fossil_retry(err: "Failed to clone #{source}") do
+        # We checkout the working directory so that "." is meaningful.
+        #
+        # An alternative would be to use the `@` bookmark, but only as long
+        # as nothing new is committed.
+        run_in_current_folder "fossil clone #{Process.quote(source)} #{Process.quote(path)}.fossil"
+      end
+    end
+
+    private def fetch_repository
+      fossil_retry(err: "Failed to update #{fossil_url}") do
+        run "fossil pull -R #{Process.quote(local_fossil_file)}"
+      end
+    end
+
+    private def fossil_retry(err = "Failed to fetch repository")
+      retries = 0
+      loop do
+        yield
+        break
+      rescue Error
+        retries += 1
+        next if retries < 3
+        raise Error.new(err)
+      end
+    end
+
+    private def delete_repository
+      Log.debug { "rm -rf #{Process.quote(local_path)}'" }
+      Shards::Helpers.rm_rf(local_path)
+      @origin_url = nil
+    end
+
+    private def cloned_repository?
+      Dir.exists?(local_path)
+    end
+
+    private def valid_repository?
+      File.each_line(File.join(local_path, "config")) do |line|
+        return true if line =~ /mirror\s*=\s*true/
+      end
+      false
+    end
+
+    private def origin_url
+      @origin_url ||= capture("fossil remote-url -R #{Process.quote(local_fossil_file)}").strip
+    end
+
+    # Returns whether origin URLs have differing hosts and/or paths.
+    protected def origin_changed?
+      return false if origin_url == fossil_url
+      return true if origin_url.nil? || fossil_url.nil?
+
+      origin_parsed = parse_uri(origin_url)
+      fossil_parsed = parse_uri(fossil_url)
+
+      (origin_parsed.host != fossil_parsed.host) || (origin_parsed.path != fossil_parsed.path)
+    end
+
+    # Parses a URI string
+    private def parse_uri(raw_uri)
+      # Need to check for file URIs early, otherwise generic parsing will fail on a colon.
+      if (path = raw_uri.lchop?("file://"))
+        return URI.new(scheme: "file", path: path)
+      end
+
+      # Try normal URI parsing first
+      uri = URI.parse(raw_uri)
+      return uri if uri.absolute? && !uri.opaque?
+
+      # Otherwise, assume and attempt to parse the scp-style ssh URIs
+      host, _, path = raw_uri.partition(':')
+
+      if host.includes?('@')
+        user, _, host = host.partition('@')
+      end
+
+      # Normalize leading slash, matching URI parsing
+      unless path.starts_with?('/')
+        path = '/' + path
+      end
+
+      URI.new(scheme: "ssh", host: host, path: path, user: user)
+    end
+
+    private def file_exists?(ref : FossilRef, path)
+      files = capture("fossil ls -R #{Process.quote(local_fossil_file)} -r #{Process.quote(ref.to_fossil_ref)} #{Process.quote(path)}")
+      !files.strip.empty?
+    end
+
+    private def capture(command, path = local_path)
+      run(command, capture: true, path: path).not_nil!
+    end
+
+    private def run(command, path = local_path, capture = false)
+      if Shards.local? && !Dir.exists?(path)
+        dependency_name = File.basename(path, ".fossil")
+        raise Error.new("Missing repository cache for #{dependency_name.inspect}. Please run without --local to fetch it.")
+      end
+      Dir.cd(path) do
+        run_in_current_folder(command, capture)
+      end
+    end
+
+    private def run_in_current_folder(command, capture = false)
+      unless FossilResolver.has_fossil_command?
+        raise Error.new("Error missing fossil command line tool. Please install Fossil first!")
+      end
+
+      Log.debug { command }
+
+      STDERR.flush
+      output = capture ? IO::Memory.new : Process::Redirect::Close
+      error = IO::Memory.new
+      status = Process.run(command, shell: true, output: output, error: error)
+
+      if status.success?
+        output.to_s if capture
+      else
+        message = error.to_s
+        Log.debug { caller.join("\n  => ") }
+        raise Error.new("Failed #{command} (#{message}). Maybe a commit, branch or file doesn't exist?")
+      end
+    end
+
+    def report_version(version : Version) : String
+      fossil_version = parse_fossil_version(version)
+      if commit = fossil_version.commit
+        "#{fossil_version.value} at #{commit[0...7]}"
+      else
+        version.value
+      end
+    end
+
+    register_resolver "fossil", FossilResolver
+  end
+end

From 95c188d41de71b9f3a1a87c9cb4bac17833c82bb Mon Sep 17 00:00:00 2001
From: MistressRemilia <remilia@posteo.jp>
Date: Thu, 28 Oct 2021 00:51:56 -0600
Subject: [PATCH 02/23] Initial work on Fossil resolver

---
 src/config.cr           |   1 +
 src/resolvers/fossil.cr | 447 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 448 insertions(+)
 create mode 100644 src/resolvers/fossil.cr

diff --git a/src/config.cr b/src/config.cr
index 51802006..8ee8db28 100644
--- a/src/config.cr
+++ b/src/config.cr
@@ -13,6 +13,7 @@ module Shards
   VERSION_TAG           = /^v(\d+[-.][-.a-zA-Z\d]+)$/
   VERSION_AT_GIT_COMMIT = /^(\d+[-.][-.a-zA-Z\d]+)\+git\.commit\.([0-9a-f]+)$/
   VERSION_AT_HG_COMMIT  = /^(\d+[-.][-.a-zA-Z\d]+)\+hg\.commit\.([0-9a-f]+)$/
+  VERSION_AT_FOSSIL_COMMIT = /^(\d+[-.][-.a-zA-Z\d]+)\+fossil\.commit\.([0-9a-f]+)$/
 
   def self.cache_path
     @@cache_path ||= find_or_create_cache_path
diff --git a/src/resolvers/fossil.cr b/src/resolvers/fossil.cr
new file mode 100644
index 00000000..b208aed2
--- /dev/null
+++ b/src/resolvers/fossil.cr
@@ -0,0 +1,447 @@
+require "uri"
+require "./resolver"
+require "../versions"
+require "../logger"
+require "../helpers"
+
+module Shards
+  abstract struct FossilRef < Ref
+    def full_info
+      to_s
+    end
+  end
+
+  struct FossilBranchRef < FossilRef
+    def initialize(@branch : String)
+    end
+
+    def to_fossil_ref
+      @branch
+    end
+
+    def to_s(io)
+      io << "branch " << @branch
+    end
+
+    def to_yaml(yaml)
+      yaml.scalar "branch"
+      yaml.scalar @branch
+    end
+  end
+
+  struct FossilTagRef < FossilRef
+    def initialize(@tag : String)
+    end
+
+    def to_fossil_ref
+      @tag
+    end
+
+    def to_s(io)
+      io << "tag " << @tag
+    end
+
+    def to_yaml(yaml)
+      yaml.scalar "tag"
+      yaml.scalar @tag
+    end
+  end
+
+  struct FossilCommitRef < FossilRef
+    getter commit : String
+
+    def initialize(@commit : String)
+    end
+
+    def =~(other : FossilCommitRef)
+      commit.starts_with?(other.commit) || other.commit.starts_with?(commit)
+    end
+
+    def to_fossil_ref
+      @commit
+    end
+
+    def to_s(io)
+      io << "commit " << @commit[0...7]
+    end
+
+    def full_info
+      "commit #{@commit}"
+    end
+
+    def to_yaml(yaml)
+      yaml.scalar "commit"
+      yaml.scalar @commit
+    end
+  end
+
+  struct FossilTipRef < FossilRef
+    def to_fossil_ref
+      "tip"
+    end
+
+    def to_s(io)
+      io << "tip"
+    end
+
+    def to_yaml(yaml)
+      raise NotImplementedError.new("FossilTipRef is for internal use only")
+    end
+  end
+
+  class FossilResolver < Resolver
+    @@has_fossil_command : Bool?
+    @@fossil_version : String?
+
+    @origin_url : String?
+    @local_fossil_file : String?
+
+    def self.key
+      "fossil"
+    end
+
+    def self.normalize_key_source(key : String, source : String) : {String, String}
+      case key
+      when "fossil"
+        {"fossil", source}
+      else
+        raise "Unknown resolver #{key}"
+      end
+    end
+
+    protected def self.has_fossil_command?
+      if @@has_fossil_command.nil?
+        @@has_fossil_command = (Process.run("fossil version", shell: true).success? rescue false)
+      end
+      @@has_fossil_command
+    end
+
+    protected def self.fossil_version
+      @@fossil_version ||= `fossil version`[/version\s+([^\s]*)/, 1]
+    end
+
+    def read_spec(version : Version) : String?
+      update_local_cache
+      ref = fossil_ref(version)
+
+      if file_exists?(ref, SPEC_FILENAME)
+        capture("fossil cat -R #{Process.quote(local_fossil_file)} #{Process.quote(SPEC_FILENAME)} -r #{Process.quote(ref.to_fossil_ref)}")
+      else
+        Log.debug { "Missing \"#{SPEC_FILENAME}\" for #{name.inspect} at #{ref}" }
+        nil
+      end
+    end
+
+    private def spec_at_ref(ref : FossilRef, commit) : Spec
+      update_local_cache
+
+      unless file_exists?(ref, SPEC_FILENAME)
+        raise Error.new "No #{SPEC_FILENAME} was found for shard #{name.inspect} at commit #{commit}"
+      end
+
+      spec_yaml = capture("fossil cat -R #{Process.quote(local_fossil_file)} #{Process.quote(SPEC_FILENAME)} -r #{Process.quote(ref.to_fossil_ref)}")
+      begin
+        Spec.from_yaml(spec_yaml)
+      rescue error : Error
+        raise Error.new "Invalid #{SPEC_FILENAME} for shard #{name.inspect} at commit #{commit}: #{error.message}"
+      end
+    end
+
+    private def spec?(version)
+      spec(version)
+    rescue Error
+    end
+
+    def available_releases : Array(Version)
+      update_local_cache
+      versions_from_tags
+    end
+
+    def latest_version_for_ref(ref : FossilRef?) : Version
+      update_local_cache
+      ref ||= FossilTipRef.new
+      begin
+        commit = commit_sha1_at(ref)
+      rescue Error
+        raise Error.new "Could not find #{ref.full_info} for shard #{name.inspect} in the repository #{source}"
+      end
+
+      spec = spec_at_ref(ref, commit)
+      Version.new "#{spec.version.value}+fossil.commit.#{commit}"
+    end
+
+    def matches_ref?(ref : FossilRef, version : Version)
+      case ref
+      when FossilCommitRef
+        ref =~ fossil_ref(version)
+      when FossilBranchRef, FossilTipRef
+        # TODO: check if version is the branch
+        version.has_metadata?
+      else
+        # TODO: check branch and tags
+        true
+      end
+    end
+
+    protected def versions_from_tags
+      capture("fossil tag list -R #{Process.quote(local_fossil_file)}")
+        .split('\n')
+        .compact_map { |tag| Version.new($1) if tag =~ VERSION_TAG }
+    end
+
+    def install_sources(version : Version, install_path : String)
+      update_local_cache
+      ref = fossil_ref(version)
+
+      FileUtils.rm_r(install_path) if File.exists?(install_path)
+      Dir.mkdir_p(install_path)
+      Log.debug { "Local path: #{local_path}" }
+      Log.debug { "Install path: #{install_path}" }
+
+      install_fossil_file = Path[install_path].join("..", "#{name}.fossil").normalize.to_s
+      #run "fossil clone #{Process.quote(local_fossil_file)} #{install_fossil_file}"
+      run "fossil open #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)} --workdir #{install_path}"
+    end
+
+    def commit_sha1_at(ref : FossilRef)
+      capture("fossil timeline #{Process.quote(ref.to_fossil_ref)} -t ci -n 1 -F %H -R #{Process.quote(local_fossil_file)}").strip.lines[0]
+    end
+
+    def local_path
+      @local_path ||= begin
+                        uri = parse_uri(fossil_url)
+
+                        path = uri.path
+                        path = Path[path]
+                        # E.g. turns "c:\local\path.git" into "c\local\path.git". Or just drops the leading slash.
+                        if (anchor = path.anchor)
+                          path = Path[path.drive.to_s.rchop(":"), path.relative_to(anchor)]
+                        end
+
+                        if host = uri.host
+                          File.join(Shards.cache_path, host, path)
+                        else
+                          File.join(Shards.cache_path, path)
+                        end
+                      end
+    end
+
+    def local_fossil_file
+      @local_fossil_file ||= Path[local_path].join("..", "#{name}.fossil").normalize.to_s
+    end
+
+    def fossil_url
+      source.strip
+    end
+
+    def parse_requirement(params : Hash(String, String)) : Requirement
+      params.each do |key, value|
+        case key
+        when "branch"
+          return FossilBranchRef.new value
+        when "tag"
+          return FossilTagRef.new value
+        when "commit"
+          return FossilCommitRef.new value
+        else
+        end
+      end
+
+      super
+    end
+
+    record FossilVersion, value : String, commit : String? = nil
+
+    private def parse_fossil_version(version : Version) : FossilVersion
+      case version.value
+      when VERSION_REFERENCE
+        FossilVersion.new version.value
+      when VERSION_AT_FOSSIL_COMMIT
+        FossilVersion.new $1, $2
+      else
+        raise Error.new("Invalid version for fossil resolver: #{version}")
+      end
+    end
+
+    private def fossil_ref(version : Version) : FossilRef
+      fossil_version = parse_fossil_version(version)
+      if commit = fossil_version.commit
+        FossilCommitRef.new commit
+      else
+        FossilTagRef.new "v#{fossil_version.value}"
+      end
+    end
+
+    private def update_local_cache
+      if cloned_repository? && origin_changed?
+        delete_repository
+        @updated_cache = false
+      end
+
+      return if Shards.local? || @updated_cache
+      Log.info { "Fetching #{fossil_url}" }
+
+      if cloned_repository?
+        # repositories cloned with shards v0.8.0 won't fetch any new remote
+        # refs; we must delete them and clone again!
+        if valid_repository?
+          fetch_repository
+        else
+          delete_repository
+          mirror_repository
+        end
+      else
+        mirror_repository
+      end
+
+      @updated_cache = true
+    end
+
+    private def mirror_repository
+      path = local_path
+      FileUtils.rm_r(path) if File.exists?(path)
+      Dir.mkdir_p(path)
+
+      source = fossil_url
+      # Remove a "file://" from the beginning, otherwise the path might be invalid
+      # on Windows.
+      source = source.lchop("file://")
+
+      Log.debug { "Local path: #{local_path}" }
+      fossil_retry(err: "Failed to clone #{source}") do
+        # We checkout the working directory so that "." is meaningful.
+        #
+        # An alternative would be to use the `@` bookmark, but only as long
+        # as nothing new is committed.
+        run_in_current_folder "fossil clone #{Process.quote(source)} #{Process.quote(path)}.fossil"
+      end
+    end
+
+    private def fetch_repository
+      fossil_retry(err: "Failed to update #{fossil_url}") do
+        run "fossil pull -R #{Process.quote(local_fossil_file)}"
+      end
+    end
+
+    private def fossil_retry(err = "Failed to fetch repository")
+      retries = 0
+      loop do
+        yield
+        break
+      rescue Error
+        retries += 1
+        next if retries < 3
+        raise Error.new(err)
+      end
+    end
+
+    private def delete_repository
+      Log.debug { "rm -rf #{Process.quote(local_path)}'" }
+      Shards::Helpers.rm_rf(local_path)
+      @origin_url = nil
+    end
+
+    private def cloned_repository?
+      Dir.exists?(local_path)
+    end
+
+    private def valid_repository?
+      File.each_line(File.join(local_path, "config")) do |line|
+        return true if line =~ /mirror\s*=\s*true/
+      end
+      false
+    end
+
+    private def origin_url
+      @origin_url ||= capture("fossil remote-url -R #{Process.quote(local_fossil_file)}").strip
+    end
+
+    # Returns whether origin URLs have differing hosts and/or paths.
+    protected def origin_changed?
+      return false if origin_url == fossil_url
+      return true if origin_url.nil? || fossil_url.nil?
+
+      origin_parsed = parse_uri(origin_url)
+      fossil_parsed = parse_uri(fossil_url)
+
+      (origin_parsed.host != fossil_parsed.host) || (origin_parsed.path != fossil_parsed.path)
+    end
+
+    # Parses a URI string
+    private def parse_uri(raw_uri)
+      # Need to check for file URIs early, otherwise generic parsing will fail on a colon.
+      if (path = raw_uri.lchop?("file://"))
+        return URI.new(scheme: "file", path: path)
+      end
+
+      # Try normal URI parsing first
+      uri = URI.parse(raw_uri)
+      return uri if uri.absolute? && !uri.opaque?
+
+      # Otherwise, assume and attempt to parse the scp-style ssh URIs
+      host, _, path = raw_uri.partition(':')
+
+      if host.includes?('@')
+        user, _, host = host.partition('@')
+      end
+
+      # Normalize leading slash, matching URI parsing
+      unless path.starts_with?('/')
+        path = '/' + path
+      end
+
+      URI.new(scheme: "ssh", host: host, path: path, user: user)
+    end
+
+    private def file_exists?(ref : FossilRef, path)
+      files = capture("fossil ls -R #{Process.quote(local_fossil_file)} -r #{Process.quote(ref.to_fossil_ref)} #{Process.quote(path)}")
+      !files.strip.empty?
+    end
+
+    private def capture(command, path = local_path)
+      run(command, capture: true, path: path).not_nil!
+    end
+
+    private def run(command, path = local_path, capture = false)
+      if Shards.local? && !Dir.exists?(path)
+        dependency_name = File.basename(path, ".fossil")
+        raise Error.new("Missing repository cache for #{dependency_name.inspect}. Please run without --local to fetch it.")
+      end
+      Dir.cd(path) do
+        run_in_current_folder(command, capture)
+      end
+    end
+
+    private def run_in_current_folder(command, capture = false)
+      unless FossilResolver.has_fossil_command?
+        raise Error.new("Error missing fossil command line tool. Please install Fossil first!")
+      end
+
+      Log.debug { command }
+
+      STDERR.flush
+      output = capture ? IO::Memory.new : Process::Redirect::Close
+      error = IO::Memory.new
+      status = Process.run(command, shell: true, output: output, error: error)
+
+      if status.success?
+        output.to_s if capture
+      else
+        message = error.to_s
+        Log.debug { caller.join("\n  => ") }
+        raise Error.new("Failed #{command} (#{message}). Maybe a commit, branch or file doesn't exist?")
+      end
+    end
+
+    def report_version(version : Version) : String
+      fossil_version = parse_fossil_version(version)
+      if commit = fossil_version.commit
+        "#{fossil_version.value} at #{commit[0...7]}"
+      else
+        version.value
+      end
+    end
+
+    register_resolver "fossil", FossilResolver
+  end
+end

From 41e55a9ee724c654291d5029390c5d64f7041bf5 Mon Sep 17 00:00:00 2001
From: MistressRemilia <26493542+MistressRemilia@users.noreply.github.com>
Date: Thu, 28 Oct 2021 01:21:13 -0600
Subject: [PATCH 03/23] Remove unneded lines

---
 src/resolvers/fossil.cr | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/resolvers/fossil.cr b/src/resolvers/fossil.cr
index b208aed2..e3ce7882 100644
--- a/src/resolvers/fossil.cr
+++ b/src/resolvers/fossil.cr
@@ -198,8 +198,6 @@ module Shards
       Log.debug { "Local path: #{local_path}" }
       Log.debug { "Install path: #{install_path}" }
 
-      install_fossil_file = Path[install_path].join("..", "#{name}.fossil").normalize.to_s
-      #run "fossil clone #{Process.quote(local_fossil_file)} #{install_fossil_file}"
       run "fossil open #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)} --workdir #{install_path}"
     end
 

From dbc0fc20a7df46d41355a769bf1cadd05e3c48c1 Mon Sep 17 00:00:00 2001
From: MistressRemilia <26493542+MistressRemilia@users.noreply.github.com>
Date: Thu, 28 Oct 2021 02:54:28 -0600
Subject: [PATCH 04/23] Add documentation

---
 docs/shard.yml.adoc | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/docs/shard.yml.adoc b/docs/shard.yml.adoc
index 17382f00..67ca282b 100644
--- a/docs/shard.yml.adoc
+++ b/docs/shard.yml.adoc
@@ -335,6 +335,21 @@ required. When missing, Shards will install the _@_ bookmark or _tip_.
 +
 *Example:* _hg: https://hg.example.org/crystal-library_
 
+*fossil*::
+
+A Fossil repository URL (string).
++
+The URL may be https://fossil-scm.org/home/help/clone[any protocol]
+supported by Fossil, which includes SSH and HTTPS.
++
+The Fossil repository will be cloned, the list of versions (and associated
+_shard.yml_) will be extracted from Fossil tags (e.g., _v1.2.3_).
++
+One of the other attributes (_version_, _tag_, _branch_, or _commit_) is
+required. When missing, Shards will install _trunk_.
++
+*Example:* _fossil: https://fossil.example.org/crystal-library_
+
 *version*::
 A version requirement (string).
 +
@@ -357,14 +372,16 @@ the _~>_ operator has a special meaning, best shown by example:
 --
 
 *branch*::
-  Install the specified branch of a git dependency or the named branch
-  of a mercurial dependency (string).
+  Install the specified branch of a git dependency, or the named branch
+  of a mercurial or fossil dependency (string).
 
 *commit*::
-  Install the specified commit of a git or mercurial dependency (string).
+  Install the specified commit of a git, mercurial, or fossil dependency
+  (string).
 
 *tag*::
-  Install the specified tag of a git or mercurial dependency (string).
+  Install the specified tag of a git, mercurial, or fossil dependency
+  (string).
 
 *bookmark*::
   Install the specified bookmark of a mercurial dependency (string).

From aad749e882da2378a4e7ee9011880a3fa5c6d7a0 Mon Sep 17 00:00:00 2001
From: MistressRemilia <26493542+MistressRemilia@users.noreply.github.com>
Date: Thu, 28 Oct 2021 04:51:36 -0600
Subject: [PATCH 05/23] Add spec tests

---
 spec/support/factories.cr         |  95 +++++++++++++++++
 spec/support/requirement.cr       |   4 +
 spec/unit/fossil_resolver_spec.cr | 168 ++++++++++++++++++++++++++++++
 3 files changed, 267 insertions(+)
 create mode 100644 spec/unit/fossil_resolver_spec.cr

diff --git a/spec/support/factories.cr b/spec/support/factories.cr
index 400cbc1a..090cd6c9 100644
--- a/spec/support/factories.cr
+++ b/spec/support/factories.cr
@@ -156,6 +156,86 @@ def checkout_hg_rev(project, rev)
   end
 end
 
+def create_fossil_repository(project, *versions)
+  Dir.cd(tmp_path) do
+    run "fossil init #{Process.quote(project)}.fossil"
+    run "fossil open #{Process.quote(project)}.fossil --workdir #{Process.quote(fossil_path(project))}"
+  end
+
+  Dir.mkdir(File.join(fossil_path(project), "src"))
+  File.write(File.join(fossil_path(project), "src", "#{project}.cr"), "module #{project.capitalize}\nend")
+
+  Dir.cd(fossil_path(project)) do
+    run %|fossil add #{Process.quote("src/#{project}.cr")}|
+  end
+
+  versions.each { |version| create_fossil_release project, version, tag: "v#{version}" }
+end
+
+def create_fossil_release(project, version, shard : Bool | NamedTuple = true, tag : String? = nil)
+  create_fossil_version_commit(project, version, shard, tag)
+end
+
+def create_fossil_version_commit(project, version, shard : Bool | NamedTuple = true, tag : String? = nil)
+  Dir.cd(fossil_path(project)) do
+    if shard
+      contents = shard.is_a?(NamedTuple) ? shard : nil
+      create_shard project, version, contents
+    end
+
+    name = shard[:name]? if shard.is_a?(NamedTuple)
+    name ||= project
+    File.touch "src/#{name}.cr"
+    run "fossil addremove"
+
+    create_fossil_commit project, "release: v#{version}", tag
+  end
+end
+
+def create_fossil_commit(project, message = "new commit", tag : String? = nil)
+  Dir.cd(fossil_path(project)) do
+    File.write("src/#{project}.cr", "# #{message}", mode: "a")
+    run "fossil addremove"
+
+    # Use --hash here to work around a file that's changed, but the size and
+    # mtime are the same.  Depending on the resolution of mtime on the
+    # underlying filesystem, shard.yml may fall into this edge case during
+    # testing.
+    #
+    # https://fossil-users.fossil-scm.narkive.com/9ybRAo1U/error-file-is-different-on-disk-compared-to-the-repository-during-commti
+    if tag
+      run "fossil commit --hash --tag #{Process.quote(tag)} -m #{Process.quote(message)}"
+    else
+      run "fossil commit --hash -m #{Process.quote(message)}"
+    end
+  end
+end
+
+def create_fork_fossil_repository(project, upstream)
+  Dir.cd(tmp_path) do
+    run "fossil clone #{Process.quote(fossil_url(upstream))} #{Process.quote(project)}"
+  end
+end
+
+def create_fossil_tag(project, version)
+  Dir.cd(fossil_path(project)) do
+    run "fossil tag add #{Process.quote(version)} current"
+  end
+end
+
+def checkout_new_fossil_branch(project, branch)
+  Dir.cd(fossil_path(project)) do
+    run "fossil branch new #{Process.quote(branch)} current"
+    run "fossil checkout branch"
+  end
+end
+
+def checkout_fossil_rev(project, rev)
+  Dir.cd(fossil_path(project)) do
+    run "fossil checkout #{Process.quote(rev)}"
+  end
+end
+
 def create_shard(project, version, contents : NamedTuple? = nil)
   spec = {name: project, version: version, crystal: Shards.crystal_version}
   spec = spec.merge(contents) if contents
@@ -206,6 +286,20 @@ def hg_path(project)
   File.join(tmp_path, project.to_s)
 end
 
+def fossil_commits(project, rev = "trunk")
+  Dir.cd(fossil_path(project)) do
+    run("fossil timeline #{Process.quote(rev)} -t ci -F %H").strip.split('\n')[..-2]
+  end
+end
+
+def fossil_url(project)
+  "file://#{Path[fossil_path(project)].to_posix}"
+end
+
+def fossil_path(project)
+  File.join(tmp_path, "#{project.to_s}")
+end
+
 def rel_path(project)
   "../../spec/.repositories/#{project}"
 end
@@ -244,6 +338,7 @@ def run(command, *, env = nil)
     # FIXME: Concurrent streams are currently broken on Windows. Need to drop one for now.
     error = nil
   {% end %}
+
   status = Process.run(command, shell: true, env: cmd_env, output: output, error: error || Process::Redirect::Close)
 
   if status.success?
diff --git a/spec/support/requirement.cr b/spec/support/requirement.cr
index e308dbde..b000cbc5 100644
--- a/spec/support/requirement.cr
+++ b/spec/support/requirement.cr
@@ -14,6 +14,10 @@ def hg_branch(name)
   Shards::HgBranchRef.new(name)
 end
 
+def fossil_branch(name)
+  Shards::FossilBranchRef.new(name)
+end
+
 def version(version)
   Shards::Version.new(version)
 end
diff --git a/spec/unit/fossil_resolver_spec.cr b/spec/unit/fossil_resolver_spec.cr
new file mode 100644
index 00000000..9906c11e
--- /dev/null
+++ b/spec/unit/fossil_resolver_spec.cr
@@ -0,0 +1,168 @@
+require "./spec_helper"
+
+private def resolver(name)
+  Shards::FossilResolver.new(name, fossil_url(name))
+end
+
+module Shards
+  # Allow overriding `source` for the specs
+  class FossilResolver
+    def source=(@source)
+      @origin_url = nil # This needs to be cleared so that #origin_url re-runs `fossil remote-url`
+    end
+  end
+
+  describe FossilResolver do
+    before_each do
+      create_fossil_repository "empty"
+      create_fossil_commit "empty", "initial release"
+
+      create_fossil_repository "unreleased"
+      create_fossil_version_commit "unreleased", "0.1.0"
+      checkout_new_fossil_branch "unreleased", "branch"
+      create_fossil_commit "unreleased", "testing"
+      checkout_fossil_rev "unreleased", "trunk"
+
+      create_fossil_repository "unreleased-bm"
+      create_fossil_version_commit "unreleased-bm", "0.1.0"
+      create_fossil_commit "unreleased-bm", "testing"
+      checkout_fossil_rev "unreleased-bm", "trunk"
+
+      create_fossil_repository "library", "0.0.1", "0.1.0", "0.1.1", "0.1.2", "0.2.0"
+
+      # Create a version tag not prefixed by 'v' which should be ignored
+      create_fossil_tag "library", "99.9.9"
+    end
+
+    it "normalizes sources" do
+      # don't normalise other domains
+      FossilResolver.normalize_key_source("fossil", "HTTPs://myfossilserver.com/Repo").should eq({"fossil", "HTTPs://myfossilserver.com/Repo"})
+
+      # don't change protocol from ssh
+      FossilResolver.normalize_key_source("fossil", "ssh://fossil@myfossilserver.com/Repo").should eq({"fossil", "ssh://fossil@myfossilserver.com/Repo"})
+    end
+
+    it "available releases" do
+      # Since we're working with the local filesystem, we need to use the .fossil files
+      resolver("empty.fossil").available_releases.should be_empty
+      resolver("library.fossil").available_releases.should eq(versions ["0.0.1", "0.1.0", "0.1.1", "0.1.2", "0.2.0"])
+    end
+
+    it "latest version for ref" do
+      expect_raises(Shards::Error, "No shard.yml was found for shard \"empty.fossil\" at commit #{fossil_commits(:empty)[0]}") do
+        resolver("empty.fossil").latest_version_for_ref(fossil_branch "tip")
+      end
+      expect_raises(Shards::Error, "No shard.yml was found for shard \"empty.fossil\" at commit #{fossil_commits(:empty)[0]}") do
+        resolver("empty.fossil").latest_version_for_ref(nil)
+      end
+      resolver("unreleased.fossil").latest_version_for_ref(fossil_branch "trunk").should eq(version "0.1.0+fossil.commit.#{fossil_commits(:unreleased)[0]}")
+      resolver("unreleased.fossil").latest_version_for_ref(fossil_branch "branch").should eq(version "0.1.0+fossil.commit.#{fossil_commits(:unreleased, "branch")[0]}")
+      resolver("unreleased.fossil").latest_version_for_ref(nil).should eq(version "0.1.0+fossil.commit.#{fossil_commits(:unreleased)[0]}")
+      resolver("unreleased-bm.fossil").latest_version_for_ref(fossil_branch "trunk").should eq(version "0.1.0+fossil.commit.#{fossil_commits("unreleased-bm")[0]}")
+      resolver("unreleased-bm.fossil").latest_version_for_ref(nil).should eq(version "0.1.0+fossil.commit.#{fossil_commits("unreleased-bm")[0]}")
+      resolver("library.fossil").latest_version_for_ref(fossil_branch "trunk").should eq(version "0.2.0+fossil.commit.#{fossil_commits(:library)[0]}")
+      resolver("library.fossil").latest_version_for_ref(nil).should eq(version "0.2.0+fossil.commit.#{fossil_commits(:library)[0]}")
+      expect_raises(Shards::Error, "Could not find branch foo for shard \"library.fossil\" in the repository #{fossil_url(:library)}") do
+        resolver("library.fossil").latest_version_for_ref(fossil_branch "foo")
+      end
+    end
+
+    it "versions for" do
+      expect_raises(Shards::Error, "No shard.yml was found for shard \"empty.fossil\" at commit #{fossil_commits(:empty)[0]}") do
+        resolver("empty.fossil").versions_for(Any)
+      end
+      resolver("library.fossil").versions_for(Any).should eq(versions ["0.0.1", "0.1.0", "0.1.1", "0.1.2", "0.2.0"])
+      resolver("library.fossil").versions_for(VersionReq.new "~> 0.1.0").should eq(versions ["0.1.0", "0.1.1", "0.1.2"])
+      resolver("library.fossil").versions_for(fossil_branch "trunk").should eq(versions ["0.2.0+fossil.commit.#{fossil_commits(:library)[0]}"])
+      resolver("unreleased.fossil").versions_for(fossil_branch "trunk").should eq(versions ["0.1.0+fossil.commit.#{fossil_commits(:unreleased)[0]}"])
+      resolver("unreleased.fossil").versions_for(Any).should eq(versions ["0.1.0+fossil.commit.#{fossil_commits(:unreleased)[0]}"])
+      resolver("unreleased-bm.fossil").versions_for(fossil_branch "trunk").should eq(versions ["0.1.0+fossil.commit.#{fossil_commits("unreleased-bm")[0]}"])
+      resolver("unreleased-bm.fossil").versions_for(Any).should eq(versions ["0.1.0+fossil.commit.#{fossil_commits("unreleased-bm")[0]}"])
+    end
+
+    it "read spec for release" do
+      spec = resolver("library.fossil").spec(version "0.1.1")
+      spec.original_version.should eq(version "0.1.1")
+      spec.version.should eq(version "0.1.1")
+    end
+
+    it "read spec for commit" do
+      version = version("0.2.0+fossil.commit.#{fossil_commits(:library)[0]}")
+      spec = resolver("library.fossil").spec(version)
+      spec.original_version.should eq(version "0.2.0")
+      spec.version.should eq(version)
+    end
+
+    it "install" do
+      library = resolver("library.fossil")
+
+      library.install_sources(version("0.1.2"), install_path("library"))
+      File.exists?(install_path("library", "src/library.cr")).should be_true
+      File.exists?(install_path("library", "shard.yml")).should be_true
+      Spec.from_file(install_path("library", "shard.yml")).version.should eq(version "0.1.2")
+
+      library.install_sources(version("0.2.0"), install_path("library"))
+      Spec.from_file(install_path("library", "shard.yml")).version.should eq(version "0.2.0")
+    end
+
+    it "install commit" do
+      library = resolver("library.fossil")
+      version = version "0.2.0+fossil.commit.#{fossil_commits(:library)[0]}"
+      library.install_sources(version, install_path("library"))
+      Spec.from_file(install_path("library", "shard.yml")).version.should eq(version "0.2.0")
+    end
+
+    it "origin changed" do
+      library = FossilResolver.new("library", fossil_url("library.fossil"))
+      library.install_sources(version("0.1.2"), install_path("library"))
+
+      # Change the origin in the cache repo to https://foss.heptapod.net/foo/bar
+      Dir.cd(library.local_path) do
+        run "fossil remote-url -R #{library.name}.fossil https://foss.heptapod.net/foo/bar"
+      end
+
+      # All of these alternatives should not trigger origin as changed
+      same_origins = [
+        "https://foss.heptapod.net/foo/bar",
+        "https://foss.heptapod.net:1234/foo/bar",
+        "http://foss.heptapod.net/foo/bar",
+        "ssh://foss.heptapod.net/foo/bar",
+        "bob@foss.heptapod.net:foo/bar",
+        "foss.heptapod.net:foo/bar",
+      ]
+
+      same_origins.each do |origin|
+        library.source = origin
+        library.origin_changed?.should be_false
+      end
+
+      # These alternatives should all trigger origin as changed
+      changed_origins = [
+        "https://foss.heptapod.net/foo/bar2",
+        "https://foss.heptapod.net/foos/bar",
+        "https://hghubz.com/foo/bar",
+        "file:///foss.heptapod.net/foo/bar",
+        "hg@foss.heptapod.net:foo/bar2",
+        "hg@foss.heptapod2.net.com:foo/bar",
+        "",
+      ]
+
+      changed_origins.each do |origin|
+        library.source = origin
+        library.origin_changed?.should be_true
+      end
+    end
+
+    it "renders report version" do
+      resolver("library.fossil").report_version(version "1.2.3").should eq("1.2.3")
+      resolver("library.fossil").report_version(version "1.2.3+fossil.commit.654875c9dbfa8d72fba70d65fd548d51ffb85aff").should eq("1.2.3 at 654875c")
+    end
+
+    it "#matches_ref" do
+      resolver = FossilResolver.new("", "")
+      resolver.matches_ref?(FossilCommitRef.new("1234567890abcdef"), Shards::Version.new("0.1.0.+fossil.commit.1234567")).should be_true
+      resolver.matches_ref?(FossilCommitRef.new("1234567890abcdef"), Shards::Version.new("0.1.0.+fossil.commit.1234567890abcdef")).should be_true
+      resolver.matches_ref?(FossilCommitRef.new("1234567"), Shards::Version.new("0.1.0.+fossil.commit.1234567890abcdef")).should be_true
+    end
+  end
+end

From c15fdd8876cd78342e2ad2187f654701e2648ed9 Mon Sep 17 00:00:00 2001
From: MistressRemilia <26493542+MistressRemilia@users.noreply.github.com>
Date: Thu, 28 Oct 2021 04:51:59 -0600
Subject: [PATCH 06/23] Fix FossilResolver so that it passes the specs.

* Use "trunk", not "tip"
* We don't need to actually open the Fossil repos in the cache once they're downloaded.
---
 src/resolvers/fossil.cr | 43 ++++++++++++++++++-----------------------
 1 file changed, 19 insertions(+), 24 deletions(-)

diff --git a/src/resolvers/fossil.cr b/src/resolvers/fossil.cr
index e3ce7882..f7b1520c 100644
--- a/src/resolvers/fossil.cr
+++ b/src/resolvers/fossil.cr
@@ -75,17 +75,17 @@ module Shards
     end
   end
 
-  struct FossilTipRef < FossilRef
+  struct FossilTrunkRef < FossilRef
     def to_fossil_ref
-      "tip"
+      "trunk"
     end
 
     def to_s(io)
-      io << "tip"
+      io << "trunk"
     end
 
     def to_yaml(yaml)
-      raise NotImplementedError.new("FossilTipRef is for internal use only")
+      raise NotImplementedError.new("FossilTrunkRef is for internal use only")
     end
   end
 
@@ -135,7 +135,7 @@ module Shards
     private def spec_at_ref(ref : FossilRef, commit) : Spec
       update_local_cache
 
-      unless file_exists?(ref, SPEC_FILENAME)
+      unless capture("fossil ls -R #{Process.quote(local_fossil_file)} -r #{Process.quote(ref.to_fossil_ref)} #{Process.quote(SPEC_FILENAME)}").strip == SPEC_FILENAME
         raise Error.new "No #{SPEC_FILENAME} was found for shard #{name.inspect} at commit #{commit}"
       end
 
@@ -159,7 +159,7 @@ module Shards
 
     def latest_version_for_ref(ref : FossilRef?) : Version
       update_local_cache
-      ref ||= FossilTipRef.new
+      ref ||= FossilTrunkRef.new
       begin
         commit = commit_sha1_at(ref)
       rescue Error
@@ -174,7 +174,7 @@ module Shards
       case ref
       when FossilCommitRef
         ref =~ fossil_ref(version)
-      when FossilBranchRef, FossilTipRef
+      when FossilBranchRef, FossilTrunkRef
         # TODO: check if version is the branch
         version.has_metadata?
       else
@@ -217,7 +217,7 @@ module Shards
                         end
 
                         if host = uri.host
-                          File.join(Shards.cache_path, host, path)
+                          File.join(Shards.cache_path, host)
                         else
                           File.join(Shards.cache_path, path)
                         end
@@ -225,7 +225,7 @@ module Shards
     end
 
     def local_fossil_file
-      @local_fossil_file ||= Path[local_path].join("..", "#{name}.fossil").normalize.to_s
+      @local_fossil_file ||= Path[local_path].join("#{name}.fossil").normalize.to_s
     end
 
     def fossil_url
@@ -297,21 +297,17 @@ module Shards
 
     private def mirror_repository
       path = local_path
-      FileUtils.rm_r(path) if File.exists?(path)
+      fossil_file = Path[path].join("#{name}.fossil").to_s
       Dir.mkdir_p(path)
+      FileUtils.rm(fossil_file) if File.exists?(fossil_file)
 
       source = fossil_url
       # Remove a "file://" from the beginning, otherwise the path might be invalid
       # on Windows.
       source = source.lchop("file://")
 
-      Log.debug { "Local path: #{local_path}" }
       fossil_retry(err: "Failed to clone #{source}") do
-        # We checkout the working directory so that "." is meaningful.
-        #
-        # An alternative would be to use the `@` bookmark, but only as long
-        # as nothing new is committed.
-        run_in_current_folder "fossil clone #{Process.quote(source)} #{Process.quote(path)}.fossil"
+        run_in_current_folder "fossil clone #{Process.quote(source)} #{Process.quote(fossil_file)}"
       end
     end
 
@@ -326,16 +322,19 @@ module Shards
       loop do
         yield
         break
-      rescue Error
+      rescue inner_err : Error
         retries += 1
         next if retries < 3
-        raise Error.new(err)
+        Log.debug { inner_err }
+        raise Error.new("#{err}: #{inner_err}")
       end
     end
 
     private def delete_repository
       Log.debug { "rm -rf #{Process.quote(local_path)}'" }
       Shards::Helpers.rm_rf(local_path)
+      Log.debug { "rm -rf #{Process.quote(local_fossil_file)}'" }
+      Shards::Helpers.rm_rf(local_fossil_file)
       @origin_url = nil
     end
 
@@ -344,13 +343,10 @@ module Shards
     end
 
     private def valid_repository?
-      File.each_line(File.join(local_path, "config")) do |line|
-        return true if line =~ /mirror\s*=\s*true/
-      end
-      false
+      File.exists?(local_fossil_file)
     end
 
-    private def origin_url
+    protected def origin_url
       @origin_url ||= capture("fossil remote-url -R #{Process.quote(local_fossil_file)}").strip
     end
 
@@ -426,7 +422,6 @@ module Shards
         output.to_s if capture
       else
         message = error.to_s
-        Log.debug { caller.join("\n  => ") }
         raise Error.new("Failed #{command} (#{message}). Maybe a commit, branch or file doesn't exist?")
       end
     end

From d33c81aad1af8d108ccfd0a661ae822ecbbae673 Mon Sep 17 00:00:00 2001
From: MistressRemilia <26493542+MistressRemilia@users.noreply.github.com>
Date: Thu, 28 Oct 2021 04:54:56 -0600
Subject: [PATCH 07/23] Install fossil

---
 .circleci/config.yml | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index f4f43c23..132f6bd8 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -52,8 +52,8 @@ jobs:
       - image: crystallang/crystal:latest
     steps:
       - run:
-          name: Install mercurial
-          command: apt-get update && apt-get install mercurial -y
+          name: Install mercurial and fossil
+          command: apt-get update && apt-get install mercurial fossil -y
       - shards-make-test
 
   test-on-osx:
@@ -63,8 +63,8 @@ jobs:
       - with-brew-cache:
           steps:
             - run:
-                name: Install Crystal and Mercurial
-                command: brew install crystal mercurial
+                name: Install Crystal, Mercurial, and Fossil
+                command: brew install crystal mercurial fossil
       - shards-make-test
 
   test-on-nightly:
@@ -72,8 +72,8 @@ jobs:
       - image: crystallang/crystal:nightly
     steps:
       - run:
-          name: Install mercurial
-          command: apt-get update && apt-get install mercurial -y
+          name: Install mercurial and fossil
+          command: apt-get update && apt-get install mercurial fossil -y
       - shards-make-test
 
 workflows:

From 5b816d14573ac580ccdd069e9db388357ffd660f Mon Sep 17 00:00:00 2001
From: MistressRemilia <26493542+MistressRemilia@users.noreply.github.com>
Date: Thu, 28 Oct 2021 05:21:44 -0600
Subject: [PATCH 08/23] Install fossil (I hope)

---
 .github/workflows/ci.yml | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a610fdb3..4930ba88 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -40,6 +40,22 @@ jobs:
         with:
           crystal: ${{ matrix.crystal }}
 
+      - name: Install Fossil
+        if: ${{ matrix.os == 'ubuntu-latest' }}
+        run: |
+          sudo apt-get update
+          sudo apt-get install fossil
+
+      - name: Install Fossil
+        if: ${{ matrix.os == 'macos-latest' }}
+        run: |
+          brew update
+          brew install fossil
+
+      - name: Install Fossil
+        if: ${{ matrix.os == 'windows-latest' }}
+        run: choco install fossil
+
       - name: Download source
         uses: actions/checkout@v2
 

From 5ae7bcd99e8f6116df491c201fd27be33cb02b82 Mon Sep 17 00:00:00 2001
From: MistressRemilia <26493542+MistressRemilia@users.noreply.github.com>
Date: Thu, 28 Oct 2021 05:49:12 -0600
Subject: [PATCH 09/23] Format using `crystal tool format`

---
 src/config.cr           |  8 ++++----
 src/resolvers/fossil.cr | 30 +++++++++++++++---------------
 2 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/src/config.cr b/src/config.cr
index 8ee8db28..ad5fe113 100644
--- a/src/config.cr
+++ b/src/config.cr
@@ -9,10 +9,10 @@ module Shards
   DEFAULT_COMMAND = "install"
   DEFAULT_VERSION = "0"
 
-  VERSION_REFERENCE     = /^v?\d+[-.][-.a-zA-Z\d]+$/
-  VERSION_TAG           = /^v(\d+[-.][-.a-zA-Z\d]+)$/
-  VERSION_AT_GIT_COMMIT = /^(\d+[-.][-.a-zA-Z\d]+)\+git\.commit\.([0-9a-f]+)$/
-  VERSION_AT_HG_COMMIT  = /^(\d+[-.][-.a-zA-Z\d]+)\+hg\.commit\.([0-9a-f]+)$/
+  VERSION_REFERENCE        = /^v?\d+[-.][-.a-zA-Z\d]+$/
+  VERSION_TAG              = /^v(\d+[-.][-.a-zA-Z\d]+)$/
+  VERSION_AT_GIT_COMMIT    = /^(\d+[-.][-.a-zA-Z\d]+)\+git\.commit\.([0-9a-f]+)$/
+  VERSION_AT_HG_COMMIT     = /^(\d+[-.][-.a-zA-Z\d]+)\+hg\.commit\.([0-9a-f]+)$/
   VERSION_AT_FOSSIL_COMMIT = /^(\d+[-.][-.a-zA-Z\d]+)\+fossil\.commit\.([0-9a-f]+)$/
 
   def self.cache_path
diff --git a/src/resolvers/fossil.cr b/src/resolvers/fossil.cr
index f7b1520c..4370a5d0 100644
--- a/src/resolvers/fossil.cr
+++ b/src/resolvers/fossil.cr
@@ -207,21 +207,21 @@ module Shards
 
     def local_path
       @local_path ||= begin
-                        uri = parse_uri(fossil_url)
-
-                        path = uri.path
-                        path = Path[path]
-                        # E.g. turns "c:\local\path.git" into "c\local\path.git". Or just drops the leading slash.
-                        if (anchor = path.anchor)
-                          path = Path[path.drive.to_s.rchop(":"), path.relative_to(anchor)]
-                        end
-
-                        if host = uri.host
-                          File.join(Shards.cache_path, host)
-                        else
-                          File.join(Shards.cache_path, path)
-                        end
-                      end
+        uri = parse_uri(fossil_url)
+
+        path = uri.path
+        path = Path[path]
+        # E.g. turns "c:\local\path.git" into "c\local\path.git". Or just drops the leading slash.
+        if (anchor = path.anchor)
+          path = Path[path.drive.to_s.rchop(":"), path.relative_to(anchor)]
+        end
+
+        if host = uri.host
+          File.join(Shards.cache_path, host)
+        else
+          File.join(Shards.cache_path, path)
+        end
+      end
     end
 
     def local_fossil_file

From fbbf336e77c2a87fca82784c18fb258f95da64e7 Mon Sep 17 00:00:00 2001
From: MistressRemilia <26493542+MistressRemilia@users.noreply.github.com>
Date: Thu, 28 Oct 2021 05:52:46 -0600
Subject: [PATCH 10/23] Be sure USER is set in the environment on Linux

---
 .circleci/config.yml | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 132f6bd8..c4b778b7 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -54,6 +54,9 @@ jobs:
       - run:
           name: Install mercurial and fossil
           command: apt-get update && apt-get install mercurial fossil -y
+      - run:
+          name: Set environment variables
+          command: echo USER="$USER" >> "${BASH_ENV}"
       - shards-make-test
 
   test-on-osx:
@@ -70,10 +73,15 @@ jobs:
   test-on-nightly:
     docker:
       - image: crystallang/crystal:nightly
+    environment:
+      USER: fossil-user
     steps:
       - run:
           name: Install mercurial and fossil
           command: apt-get update && apt-get install mercurial fossil -y
+      - run:
+          name: Set environment variables
+          command: echo USER="$USER" >> "${BASH_ENV}"
       - shards-make-test
 
 workflows:

From 9c12b0b5a86e3da854022a3fb681b5821534a69e Mon Sep 17 00:00:00 2001
From: MistressRemilia <26493542+MistressRemilia@users.noreply.github.com>
Date: Sat, 8 Jan 2022 13:55:28 -0700
Subject: [PATCH 11/23] Use -nested when opening the Fossil repository.

This is necessary for projects that are themselves under Fossil.
---
 src/resolvers/fossil.cr | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/resolvers/fossil.cr b/src/resolvers/fossil.cr
index 4370a5d0..e412c625 100644
--- a/src/resolvers/fossil.cr
+++ b/src/resolvers/fossil.cr
@@ -198,7 +198,7 @@ module Shards
       Log.debug { "Local path: #{local_path}" }
       Log.debug { "Install path: #{install_path}" }
 
-      run "fossil open #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)} --workdir #{install_path}"
+      run "fossil open -nested #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)} --workdir #{install_path}"
     end
 
     def commit_sha1_at(ref : FossilRef)

From 39c41e23a88fe03cfb23958fa321fcfc5d5ef56c Mon Sep 17 00:00:00 2001
From: MistressRemilia <26493542+MistressRemilia@users.noreply.github.com>
Date: Sun, 30 Jan 2022 15:36:27 -0700
Subject: [PATCH 12/23] spec: Use CIRCLE_PROJECT_USERNAME instead of USER for
 the username environment.

---
 .circleci/config.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index c4b778b7..4b200ae9 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -56,7 +56,7 @@ jobs:
           command: apt-get update && apt-get install mercurial fossil -y
       - run:
           name: Set environment variables
-          command: echo USER="$USER" >> "${BASH_ENV}"
+          command: echo USER="$CIRCLE_PROJECT_USERNAME" >> "${BASH_ENV}"
       - shards-make-test
 
   test-on-osx:
@@ -76,7 +76,7 @@ jobs:
     environment:
       USER: fossil-user
     steps:
-      - run:
+      - run:yes
           name: Install mercurial and fossil
           command: apt-get update && apt-get install mercurial fossil -y
       - run:

From 5fa397de14431382fcba2484669b2528d70f3085 Mon Sep 17 00:00:00 2001
From: MistressRemilia <26493542+MistressRemilia@users.noreply.github.com>
Date: Mon, 31 Jan 2022 02:46:37 -0700
Subject: [PATCH 13/23] Fix syntax error

---
 .circleci/config.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 4b200ae9..bc72c068 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -76,7 +76,7 @@ jobs:
     environment:
       USER: fossil-user
     steps:
-      - run:yes
+      - run:
           name: Install mercurial and fossil
           command: apt-get update && apt-get install mercurial fossil -y
       - run:

From 0b07b11d9ebd4271d0da40053b3667f451fa7c1f Mon Sep 17 00:00:00 2001
From: MistressRemilia <4798372-RemiliaScarlet@users.noreply.gitlab.com>
Date: Mon, 31 Jan 2022 22:21:18 -0700
Subject: [PATCH 14/23] Add workaround for older Fossil versions that don't
 have the --workdir argument for open.

---
 src/resolvers/fossil.cr | 32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/resolvers/fossil.cr b/src/resolvers/fossil.cr
index e412c625..8ba10968 100644
--- a/src/resolvers/fossil.cr
+++ b/src/resolvers/fossil.cr
@@ -91,6 +91,8 @@ module Shards
 
   class FossilResolver < Resolver
     @@has_fossil_command : Bool?
+    @@fossil_version_maj : Int8?
+    @@fossil_version_min : Int8?
     @@fossil_version : String?
 
     @origin_url : String?
@@ -117,7 +119,24 @@ module Shards
     end
 
     protected def self.fossil_version
-      @@fossil_version ||= `fossil version`[/version\s+([^\s]*)/, 1]
+      unless @@fossil_version
+        @@fossil_version = `fossil version`[/version\s+([^\s]*)/, 1]
+        maj, min = @@fossil_version.not_nil!.split('.').map &.to_i8
+        @@fossil_version_maj = maj
+        @@fossil_version_min = min
+      end
+
+      @@fossil_version
+    end
+
+    protected def self.fossil_version_maj
+      self.fossil_version unless @@fossil_version_maj
+      @@fossil_version_maj.not_nil!
+    end
+
+    protected def self.fossil_version_min
+      self.fossil_version unless @@fossil_version_min
+      @@fossil_version_min.not_nil!
     end
 
     def read_spec(version : Version) : String?
@@ -198,7 +217,16 @@ module Shards
       Log.debug { "Local path: #{local_path}" }
       Log.debug { "Install path: #{install_path}" }
 
-      run "fossil open -nested #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)} --workdir #{install_path}"
+      # The --workdir argument was introduced in version 2.12, so we have to
+      # fake it
+      if FossilResolver.fossil_version_maj <= 2 &&
+         FossilResolver.fossil_version_min <= 12
+        Dir.cd(install_path) do
+          run "fossil open -nested #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)}"
+        end
+      else
+        run "fossil open -nested #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)} --workdir #{install_path}"
+      end
     end
 
     def commit_sha1_at(ref : FossilRef)

From ff419d158e82bf9e68d270443dd3deb0aff6f3c2 Mon Sep 17 00:00:00 2001
From: MistressRemilia <4798372-RemiliaScarlet@users.noreply.gitlab.com>
Date: Mon, 31 Jan 2022 22:21:57 -0700
Subject: [PATCH 15/23] Try something different with user environment variables
 *sigh*

---
 .circleci/config.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index bc72c068..3c838172 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -56,7 +56,7 @@ jobs:
           command: apt-get update && apt-get install mercurial fossil -y
       - run:
           name: Set environment variables
-          command: echo USER="$CIRCLE_PROJECT_USERNAME" >> "${BASH_ENV}"
+          command: echo 'export USER=$CIRCLE_PROJECT_USERNAME' >> $BASH_ENV
       - shards-make-test
 
   test-on-osx:
@@ -81,7 +81,7 @@ jobs:
           command: apt-get update && apt-get install mercurial fossil -y
       - run:
           name: Set environment variables
-          command: echo USER="$USER" >> "${BASH_ENV}"
+          command: echo 'export USER=$CIRCLE_PROJECT_USERNAME' >> $BASH_ENV
       - shards-make-test
 
 workflows:

From a3bca1239c10bdd71bb6946424fd6cc73c70a8ec Mon Sep 17 00:00:00 2001
From: MistressRemilia <4798372-RemiliaScarlet@users.noreply.gitlab.com>
Date: Mon, 31 Jan 2022 22:39:07 -0700
Subject: [PATCH 16/23] Use less than, not less than or equal.

---
 src/resolvers/fossil.cr | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/resolvers/fossil.cr b/src/resolvers/fossil.cr
index 8ba10968..9a2d6016 100644
--- a/src/resolvers/fossil.cr
+++ b/src/resolvers/fossil.cr
@@ -220,7 +220,7 @@ module Shards
       # The --workdir argument was introduced in version 2.12, so we have to
       # fake it
       if FossilResolver.fossil_version_maj <= 2 &&
-         FossilResolver.fossil_version_min <= 12
+         FossilResolver.fossil_version_min < 12
         Dir.cd(install_path) do
           run "fossil open -nested #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)}"
         end

From 9833fd0ee4dd0c0ad6c06b709dbe369ced742cf9 Mon Sep 17 00:00:00 2001
From: MistressRemilia <4798372-RemiliaScarlet@users.noreply.gitlab.com>
Date: Mon, 31 Jan 2022 22:39:52 -0700
Subject: [PATCH 17/23] Use the environment: key to export environment
 variables for jobs

---
 .circleci/config.yml | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 3c838172..fa22344f 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -50,13 +50,12 @@ jobs:
   test:
     docker:
       - image: crystallang/crystal:latest
+    environment:
+      USER: shardsuser
     steps:
       - run:
           name: Install mercurial and fossil
           command: apt-get update && apt-get install mercurial fossil -y
-      - run:
-          name: Set environment variables
-          command: echo 'export USER=$CIRCLE_PROJECT_USERNAME' >> $BASH_ENV
       - shards-make-test
 
   test-on-osx:
@@ -74,14 +73,11 @@ jobs:
     docker:
       - image: crystallang/crystal:nightly
     environment:
-      USER: fossil-user
+      USER: shardsuser
     steps:
       - run:
           name: Install mercurial and fossil
           command: apt-get update && apt-get install mercurial fossil -y
-      - run:
-          name: Set environment variables
-          command: echo 'export USER=$CIRCLE_PROJECT_USERNAME' >> $BASH_ENV
       - shards-make-test
 
 workflows:

From b911ff6d90eec1e9e87cab888dcb7e4a8df8328f Mon Sep 17 00:00:00 2001
From: MistressRemilia <4798372-RemiliaScarlet@users.noreply.gitlab.com>
Date: Tue, 1 Feb 2022 01:49:52 -0700
Subject: [PATCH 18/23] Improve support for older versions of Fossil.

Versions before 2.12 did not have a --workdir argument for the
timeline command, and were more strict about argument ordering.  This
can be faked using Dir#cd and arguments in the correct order.

Versions before 2.14 did not support the --format/-F argument for the
timeline command.  As a workaround, we can use timeline + whatis to
get the full artifact hash.
---
 src/resolvers/fossil.cr | 55 +++++++++++++++++++++++++++++++++--------
 1 file changed, 45 insertions(+), 10 deletions(-)

diff --git a/src/resolvers/fossil.cr b/src/resolvers/fossil.cr
index 9a2d6016..fdada65e 100644
--- a/src/resolvers/fossil.cr
+++ b/src/resolvers/fossil.cr
@@ -93,6 +93,7 @@ module Shards
     @@has_fossil_command : Bool?
     @@fossil_version_maj : Int8?
     @@fossil_version_min : Int8?
+    @@fossil_version_rev : Int8?
     @@fossil_version : String?
 
     @origin_url : String?
@@ -121,9 +122,10 @@ module Shards
     protected def self.fossil_version
       unless @@fossil_version
         @@fossil_version = `fossil version`[/version\s+([^\s]*)/, 1]
-        maj, min = @@fossil_version.not_nil!.split('.').map &.to_i8
-        @@fossil_version_maj = maj
-        @@fossil_version_min = min
+        pieces = @@fossil_version.not_nil!.split('.')
+        @@fossil_version_maj = pieces[0].to_i8
+        @@fossil_version_min = pieces[1].to_i8
+        @@fossil_version_rev = (pieces[2]?.try &.to_i8 || 0i8)
       end
 
       @@fossil_version
@@ -139,6 +141,11 @@ module Shards
       @@fossil_version_min.not_nil!
     end
 
+    protected def self.fossil_version_rev
+      self.fossil_version unless @@fossil_version_rev
+      @@fossil_version_rev.not_nil!
+    end
+
     def read_spec(version : Version) : String?
       update_local_cache
       ref = fossil_ref(version)
@@ -185,8 +192,11 @@ module Shards
         raise Error.new "Could not find #{ref.full_info} for shard #{name.inspect} in the repository #{source}"
       end
 
-      spec = spec_at_ref(ref, commit)
-      Version.new "#{spec.version.value}+fossil.commit.#{commit}"
+      if spec = spec_at_ref(ref, commit)
+        Version.new "#{spec.version.value}+fossil.commit.#{commit}"
+      else
+        raise Error.new "No #{SPEC_FILENAME} was found for shard #{name.inspect} at commit #{commit}"
+      end
     end
 
     def matches_ref?(ref : FossilRef, version : Version)
@@ -221,16 +231,41 @@ module Shards
       # fake it
       if FossilResolver.fossil_version_maj <= 2 &&
          FossilResolver.fossil_version_min < 12
-        Dir.cd(install_path) do
-          run "fossil open -nested #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)}"
-        end
+        Log.debug { "Opening Fossil repo #{local_fossil_file} in directory #{install_path}" }
+        run("fossil open #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)} --nested", install_path)
       else
-        run "fossil open -nested #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)} --workdir #{install_path}"
+        run "fossil open #{local_fossil_file} #{Process.quote(ref.to_fossil_ref)}  --nested --workdir #{install_path}"
       end
     end
 
     def commit_sha1_at(ref : FossilRef)
-      capture("fossil timeline #{Process.quote(ref.to_fossil_ref)} -t ci -n 1 -F %H -R #{Process.quote(local_fossil_file)}").strip.lines[0]
+      # Fossil versions before 2.14 do not support the --format/-F for the
+      # timeline command.
+      if FossilResolver.fossil_version_maj <= 2 &&
+         FossilResolver.fossil_version_min < 14
+        # Capture the short artifact name from the timeline using a regex.
+        # -W 0  = unlimited line width
+        # -n 1  = limit results to one entry
+        # -t ci = Display only checkins on the timeline
+        shortShas = capture("fossil timeline #{Process.quote(ref.to_fossil_ref)} -t ci -W 0 -n 1 -R #{Process.quote(local_fossil_file)}")
+
+        # We only want the lines with short artifact names
+        retLines = shortShas.strip.lines.flat_map do |line|
+          /^.+ \[(.+)\].*/.match(line).try &.[1]
+        end
+
+        # Remove empty results
+        retLines.reject! &.nil?
+        return "" if retLines.empty?
+
+        # Call the whatis command so we can properly expand the short artifact
+        # name to the full artifact hash.
+        whatis = capture("fossil whatis #{retLines[0]} -R #{Process.quote(local_fossil_file)}")
+        /artifact:\s+(.+)/.match(whatis).try &.[1] || ""
+      else
+        # Fossil v2.14 and newer support -F %H, so use that.
+        capture("fossil timeline #{Process.quote(ref.to_fossil_ref)} -t ci -F %H -n 1 -R #{Process.quote(local_fossil_file)}")
+      end
     end
 
     def local_path

From a5958a8e8b83628accdc695c1610085ce26adaa6 Mon Sep 17 00:00:00 2001
From: MistressRemilia <4798372-RemiliaScarlet@users.noreply.gitlab.com>
Date: Tue, 1 Feb 2022 01:52:15 -0700
Subject: [PATCH 19/23] Fix tests

---
 spec/support/factories.cr | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/spec/support/factories.cr b/spec/support/factories.cr
index 090cd6c9..03116891 100644
--- a/spec/support/factories.cr
+++ b/spec/support/factories.cr
@@ -159,7 +159,14 @@ end
 def create_fossil_repository(project, *versions)
   Dir.cd(tmp_path) do
     run "fossil init #{Process.quote(project)}.fossil"
-    run "fossil open #{Process.quote(project)}.fossil --workdir #{Process.quote(fossil_path(project))}"
+
+    # Use a workaround so we don't use --workdir in case the specs are run on a
+    # machine with an old Fossil version.  See the #install_sources method in
+    # src/resolvers/fossil.cr
+    Dir.mkdir(fossil_path(project)) unless Dir.exists?(fossil_path(project))
+    Dir.cd(fossil_path(project)) do
+      run "fossil open #{Process.quote(File.join(tmp_path, project))}.fossil"
+    end
   end
 
   Dir.mkdir(File.join(fossil_path(project), "src"))
@@ -287,8 +294,17 @@ def hg_path(project)
 end
 
 def fossil_commits(project, rev = "trunk")
+  # This is using the workaround code in case the machine running the specs is
+  # using an old Fossil version.  See the #commit_sha1_at method in
+  # src/resolvers/fossil.cr for info.
   Dir.cd(fossil_path(project)) do
-    run("fossil timeline #{Process.quote(rev)} -t ci -F %H").strip.split('\n')[..-2]
+    retStr = run("fossil timeline #{Process.quote(rev)} -t ci -W 0").strip.lines
+    retLines = retStr.flat_map do |line|
+      /^.+ \[(.+)\].*/.match(line).try &.[1]
+    end
+
+    retLines.reject! &.nil?
+    [/artifact:\s+(.+)/.match(run("fossil whatis #{retLines[0]}")).not_nil!.[1]]
   end
 end
 

From f6f036ad93f3a3ea24415597049926c044c82e0f Mon Sep 17 00:00:00 2001
From: MistressRemilia <4798372-RemiliaScarlet@users.noreply.gitlab.com>
Date: Tue, 1 Feb 2022 02:12:20 -0700
Subject: [PATCH 20/23] Use #split instead of #lines

---
 spec/support/factories.cr | 2 +-
 src/resolvers/fossil.cr   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/spec/support/factories.cr b/spec/support/factories.cr
index cce67f08..7f3e3491 100644
--- a/spec/support/factories.cr
+++ b/spec/support/factories.cr
@@ -306,7 +306,7 @@ def fossil_commits(project, rev = "trunk")
   # using an old Fossil version.  See the #commit_sha1_at method in
   # src/resolvers/fossil.cr for info.
   Dir.cd(fossil_path(project)) do
-    retStr = run("fossil timeline #{Process.quote(rev)} -t ci -W 0").strip.lines
+    retStr = run("fossil timeline #{Process.quote(rev)} -t ci -W 0").strip.split('\n')
     retLines = retStr.flat_map do |line|
       /^.+ \[(.+)\].*/.match(line).try &.[1]
     end
diff --git a/src/resolvers/fossil.cr b/src/resolvers/fossil.cr
index fdada65e..8fdf4279 100644
--- a/src/resolvers/fossil.cr
+++ b/src/resolvers/fossil.cr
@@ -250,7 +250,7 @@ module Shards
         shortShas = capture("fossil timeline #{Process.quote(ref.to_fossil_ref)} -t ci -W 0 -n 1 -R #{Process.quote(local_fossil_file)}")
 
         # We only want the lines with short artifact names
-        retLines = shortShas.strip.lines.flat_map do |line|
+        retLines = shortShas.strip.split('\n').flat_map do |line|
           /^.+ \[(.+)\].*/.match(line).try &.[1]
         end
 

From eb62bcfb9103cccef5acc67014534ddde72be1e5 Mon Sep 17 00:00:00 2001
From: Remilia Scarlet <26493542+MistressRemilia@users.noreply.github.com>
Date: Wed, 9 Feb 2022 16:30:37 -0700
Subject: [PATCH 21/23] Update .github/workflows/ci.yml
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Johannes Müller <straightshoota@gmail.com>
---
 .github/workflows/ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4930ba88..eaec8412 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -41,7 +41,7 @@ jobs:
           crystal: ${{ matrix.crystal }}
 
       - name: Install Fossil
-        if: ${{ matrix.os == 'ubuntu-latest' }}
+        if: ${{ runner.os == 'Linux' }}
         run: |
           sudo apt-get update
           sudo apt-get install fossil

From 615868af9aa4079b151c63086b2ef06b032c0b72 Mon Sep 17 00:00:00 2001
From: Remilia Scarlet <26493542+MistressRemilia@users.noreply.github.com>
Date: Wed, 9 Feb 2022 16:30:53 -0700
Subject: [PATCH 22/23] Update docs/shard.yml.adoc
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Johannes Müller <straightshoota@gmail.com>
---
 docs/shard.yml.adoc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/shard.yml.adoc b/docs/shard.yml.adoc
index 67ca282b..436af88b 100644
--- a/docs/shard.yml.adoc
+++ b/docs/shard.yml.adoc
@@ -337,7 +337,7 @@ required. When missing, Shards will install the _@_ bookmark or _tip_.
 
 *fossil*::
 
-A Fossil repository URL (string).
+A https://www.fossil-scm.org[Fossil] repository URL (string).
 +
 The URL may be https://fossil-scm.org/home/help/clone[any protocol]
 supported by Fossil, which includes SSH and HTTPS.

From 2a90c8a1ca3d1e6e4953f81045f870714737f528 Mon Sep 17 00:00:00 2001
From: MistressRemilia <4798372-RemiliaScarlet@users.noreply.gitlab.com>
Date: Wed, 9 Feb 2022 19:37:52 -0700
Subject: [PATCH 23/23] Ignore the extra '--- entry limit (1) reached ---'
 string that gets printed.

---
 src/resolvers/fossil.cr | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/resolvers/fossil.cr b/src/resolvers/fossil.cr
index 8fdf4279..eda50fb5 100644
--- a/src/resolvers/fossil.cr
+++ b/src/resolvers/fossil.cr
@@ -264,7 +264,7 @@ module Shards
         /artifact:\s+(.+)/.match(whatis).try &.[1] || ""
       else
         # Fossil v2.14 and newer support -F %H, so use that.
-        capture("fossil timeline #{Process.quote(ref.to_fossil_ref)} -t ci -F %H -n 1 -R #{Process.quote(local_fossil_file)}")
+        capture("fossil timeline #{Process.quote(ref.to_fossil_ref)} -t ci -F %H -n 1 -R #{Process.quote(local_fossil_file)}").split('\n')[0]
       end
     end