Reading a comment in pkgsrc/mk/defs.NetBSD.mk, I guess /usr/pkg/bin
/xmms, which calls dlopen(), needs to be linked against libgcc_pic.a.
This is NetBSD-specific, IIRC.

Maybe xmms's configure/make files are tweaking linker commands and
miss a line "-lgcc" (or "-lgcc_p"?), which should be automatically
added by out /usr/bin/gcc?

Masao