Either you don’t have alsa installed or it wasn’t found by CMake. SC uses 3 different MIDI backends depending on the platform it’s being compiled for. The alsa backend (which is implemented in SC_AlsaMIDI.cpp) is what’s used on Linux. It’s only enabled if alsa (both the library and development headers) is found by CMake.
What you should do is:
- install both alsa and its development headers if they’re not already installed (these are sometimes 2 different packages depending on who packages it)
- compile SC in a clean build directory and see if that solves the problem
- if it doesn’t, paste here the entire output from the CMake build system generation step, along with the locations of the alsa libraries and headers on your system. The build system generation step is the step before you compile the program.
An unbound primitive typically means that the issue is at the level of the build system / system configuration, because primitives are almost exclusively enabled and disabled there.