New comment by Hoshpak on void-packages repository

https://github.com/void-linux/void-packages/pull/15204#issuecomment-538917278

Comment:
Fails on musl:

```
c/_cffi_backend.c:15:10: fatal error: ffi.h: No such file or directory
   15 | #include <ffi.h>
      |          ^~~~~~~
```

Adding `libffi-devel` to makedepends could help since it provides the header file but I don't have time to test that right now.