+-- "-optc-pthread"
+-- , "-optl-pthread"
+ -- FreeBSD's default threading library is the KSE-based M:N libpthread,
+ -- which GHC has some problems with. It's currently not clear whether
+ -- the problems are our fault or theirs, but it seems that using the
+ -- alternative 1:1 threading library libthr works around it:
+ "-optl-lthr"
+#elif defined(solaris2_TARGET_OS)
+ "-optl-lrt"