Upstream-Issue: https://github.com/ContinuumIO/pycosat/pull/29

--- a/picosat.c
+++ b/picosat.c
@@ -8147,7 +8147,7 @@
 #ifndef NGETRUSAGE
 #include <sys/time.h>
 #include <sys/resource.h>
-#include <sys/unistd.h>
+#include <unistd.h>
 #endif
 
 double