Nice to meet you, Nick.

> It looks as though you or FreeAmp has defined _POSIX_THREAD_SYSCALL_SOFT. 

Yes, I defined it in the pkg's Makefile.

> When this is defined the pth pthread.h header will #define several things 
> like read, write, etc. This causes problems with c++ classes that have 
> members of those names. You may be lucky and have FreeAmp work without 
> _POSIX_THREAD_SYSCALL_SOFT.

Yes, when I comment it, I can build FreeAmp successfally.
But I am not lucky enough because I just got core dumped with such message:

FreeAmp has been compiled with mutex debugging enabled.
To dump mutex info: kill -SIGUSR1 15620

So I think we should define _POSIX_THREAD_SYSCALL_SOFT or wait for your
work about _POSIX_THREAD_SYSCALL_HARD, am I wrong?

Thanks for your answer!

-rxg