I've recently installed wildmidi 0.2.3.5 om my Archlinux system. Since it comes with no config file, I adopted the default timidity.cfg coming with the timidity-freepats package (which supplies the freepats patch files for software midi playback) as the /etc/wildmidi.cfg file.
By default, this file has the only two uncommented lines:
Now, when playing some midi file, no sound is produced and two error messages are given:
libWildMidi(WM_BufferFile:103): ERROR Unable to stat /etc/timidity++/freepats/Tone_000/000_Acoustic_Grand_Piano.pat (No such file or directory)
libWildMidi(WM_BufferFile:103): ERROR Unable to stat /etc/timidity++/freepats/Tone_000/001_Acoustic_Brite_Piano.pat (No such file or directory).
It seems that the location of Gravis Ultrasound compatible patch files is not respected by wildmidi (given in the dir line). Instead it erroneously prepends the dir of the config file for freepats patches (given in the source line) to the relative file path of these two patches (and presumably to any other patch file if they are required).
The workarounds I've found out were to symlink /usr/share/timidity/freepats/*_000 subdirs into /etc/timidity++/freepats/ or erase the source line from /etc/wildmidi.cfg and paste the content of /etc/timidity++/freepats/freepats.cfg.