http://bugs.winehq.org/show_bug.cgi?id=30557
--- Comment #60 from Rafał Mużyło galtgendo@o2.pl 2013-07-07 14:42:10 CDT --- (In reply to comment #58)
add -ldl somewhere..
As we're being lazy here, appending '@LIBDL@' to 'LIBPTHREAD =' line in loader/Makefile.in looks as if it should work.