diff -aruN a/CFUniChar.c b/CFUniChar.c
--- a/CFUniChar.c	2009-02-19 16:25:06.000000000 -0800
+++ b/CFUniChar.c	2012-04-25 22:58:38.968005637 -0700
@@ -221,10 +221,12 @@
 
     int no_hang_fd = open("/dev/autofs_nowait", 0);
     if ((fd = open(fileName, O_RDONLY, 0)) < 0) {
+    CFLog(__kCFLogAssertion, CFSTR("%s(): could not open %s for read-only access."), __PRETTY_FUNCTION__, fileName);
 	close(no_hang_fd);
 	return false;
     }
     if (fstat(fd, &statBuf) < 0 || (*bytes = mmap(0, statBuf.st_size, PROT_READ, MAP_PRIVATE, fd, 0)) == (void *)-1) {
+        CFLog(__kCFLogAssertion, CFSTR("%s(): could not map %s for read-only access."), __PRETTY_FUNCTION__, fileName);
         close(fd);
         return false;
     }