patch 7.4.1659
Problem:    Compiler warning for argument type. (Manuel Ortega)
Solution:   Remove "&".
diff --git a/src/os_unix.c b/src/os_unix.c
index 77c96dc..74ffe93 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -5467,7 +5467,7 @@
 	;
 
 #else
-    avail = RealWaitForChar(read_cmd_fd, msec, NULL, &break_loop);
+    avail = RealWaitForChar(read_cmd_fd, msec, NULL, break_loop);
 #endif
     return avail;
 }