Given what I just read about IncludeOS (I'm not really familiar), it feels like implementing as much of musl as possible is probably the best you can do compatibility wise. There are going to be a lot of Linux features simply incompatible with includeOS, so claiming that 400 syscalls will be implemented is unlikely.
That said - why do you have to get musl compatibility by implementing the Linux syscalls? Is contributing to musl an option?
That said - why do you have to get musl compatibility by implementing the Linux syscalls? Is contributing to musl an option?