The reason for removing <sys/poll.h> from getting included is that musl
explicitely tells to correct the code when <sys/poll.h> is included,
changing it to include <poll.h> only as the standard documents suggest!

ref: http://pubs.opengroup.org/onlinepubs/000095399/basedefs/poll.h.html

The Makefile provided by the archive contains an interesting line:
64              $(shell cd lib; git ls-files | sed 's,^,lib/,') \
that leads to an error in the build logs:
/bin/sh: git: command not found
Aparently this does not break build but investigation is needed.