The following steps were tested on a Raspberry Pi 4 device running a Debian 12.9 base system.
Install deps:
sudo apt-get install librtaudio-dev libsndfile1-dev cmake build-essential wsjtx
Install RtAudio 6.0.1:
git clone https://github.com/thestk/rtaudio.git
cd rtaudio
cmake .
make -j4
sudo make install
Build ft8modem:
git clone https://github.com/kholia/ft8modem-kk5jy.git
cd ft8modem-kk5jy
make
./ft8encode WSPR 12000 1550 sample.wav 'VU3CER MK68 31'
330202021002311022100301313002200210010120000032332211030203123020011210323010032212130203101232021220021001001112330211210223312220232300130022002112321322233200
Wrote 1345116 samples (112.093 sec).
$ wsprd sample.wav
mple 45 0.0 0.001552 0 VU3CER MK68 30
mple -21 -0.3 0.001608 0 VU3CER MK68 30
<DecodeFinished>