# also see commit 6d1baf99
diff --git src/corelib/io/qfilesystemwatcher_kqueue.cpp src/corelib/io/qfilesystemwatcher_kqueue.cpp
index cabeb44..9743649 100644
--- src/corelib/io/qfilesystemwatcher_kqueue.cpp
+++ src/corelib/io/qfilesystemwatcher_kqueue.cpp
@@ -127,6 +127,7 @@ QStringList QKqueueFileSystemWatcherEngine::addPaths(const QStringList &paths,
         while (it.hasNext()) {
             QString path = it.next();
             int fd;
+            errno = 0;
 #if defined(O_EVTONLY)
             fd = qt_safe_open(QFile::encodeName(path), O_EVTONLY);
 #else
@@ -135,15 +136,34 @@ QStringList QKqueueFileSystemWatcherEngine::addPaths(const QStringList &paths,
             if (fd == -1) {
                 perror("QKqueueFileSystemWatcherEngine::addPaths: open");
                 continue;
+            } else {
+               if (errno) {
+                    perror("QKqueueFileSystemWatcherEngine::addPaths: open returned valid descriptor but");
+                    ::close(fd);
+                    continue;
+               }
             }
+            errno = 0;
             if (fd >= (int)FD_SETSIZE / 2 && fd < (int)FD_SETSIZE) {
                 int fddup = fcntl(fd, F_DUPFD, FD_SETSIZE);
                 if (fddup != -1) {
                     ::close(fd);
                     fd = fddup;
+                } else {
+                    perror("QKqueueFileSystemWatcherEngine::addPaths: fddup");
+                    if (errno = EMFILE) {
+                        // it seems wise not to insist when we just hit the open file limit
+                        ::close(fd);
+                        continue;
+                    }
                 }
             }
+            errno = 0;
             fcntl(fd, F_SETFD, FD_CLOEXEC);
+            if (errno) {
+                perror("QKqueueFileSystemWatcherEngine::addPaths: fcntl");
+                errno = 0;
+            }
 
             QT_STATBUF st;
             if (QT_FSTAT(fd, &st) == -1) {