This happens only when I try to disable OSS (that I don't need as I use
Alsa and Jack).
After reading src/makefile.gnu, I could however compile
with OSS disabled by using:
make -f makefile.gnu JACK=true PA=false OSS=false
But doing this compiles Pd without working Jack support
That looks like a bug.
API 5 not supported, reverting to 1 (ALSA)
Anyway I simply went with OSS enabled but wanted to give some feedback
on this behavior.
Enabling OSS is not a big deal as it will only be actually compiled if the OSS headers are detected. We should fix the broken compilation when it's disabled, however.