A number of packages in the Gentoo repository will not compile under musl-libc because of the lack of backtrace support. Errors such as "fatal error: execinfo.h: No such file or directory" are a good indicator of this. One potential ultimate goal/answer to this problem is to port affected code to libunwind (http://www.nongnu.org/libunwind/index.html). In the meantime, however, we will likely simply patch affected code with an #ifdef __GLIBC__ until upstream has made appropriate changes.
