- add the Fedora Extras pushscript lock
- change the Repo.py locking and exception handling
  [and add debug output to investigate a mysterious exception in
   _update_repo() shutil.copy()]

diff -Nur plague-0.4.4.1-orig/server/PackageJob.py plague-0.4.4.1/server/PackageJob.py
--- plague-0.4.4.1-orig/server/PackageJob.py	2006-03-13 05:10:49.000000000 +0100
+++ plague-0.4.4.1/server/PackageJob.py	2007-12-30 23:13:50.000000000 +0100
@@ -701,6 +701,7 @@
 
     def _stage_repodone(self):
         resultstring = " %s (%s): Build on target %s succeeded." % (self.uid, self.name, self._target_str)
+        log(resultstring)
         self.result = 'success'
         self._set_cur_stage('needsign', resultstring)
 
diff -Nur plague-0.4.4.1-orig/server/Repo.py plague-0.4.4.1/server/Repo.py
--- plague-0.4.4.1-orig/server/Repo.py	2005-11-29 07:17:07.000000000 +0100
+++ plague-0.4.4.1/server/Repo.py	2007-12-30 21:55:34.000000000 +0100
@@ -25,6 +25,9 @@
 import EmailUtils
 from plague import DebugUtils
 
+# Lockfile used by external scripts to ensure mutual exclusion
+# from concurrent access to the repository's directory
+REPO_LOCKFILE_NAME = ".repo-update.lock"
 
 class Repo(threading.Thread):
     """ Represents an on-disk repository of RPMs and manages updates to the repo. """
@@ -41,6 +44,7 @@
         self._repodir = os.path.join(repodir, target_str)
         if not os.path.exists(self._repodir):
             os.makedirs(self._repodir)
+        self._lockfile_path = os.path.join(self._repodir, REPO_LOCKFILE_NAME)
 
         self._repo_cache_dir = os.path.join(repodir, "cache", target_str)
         if not os.path.exists(self._repo_cache_dir):
@@ -87,8 +91,29 @@
             return True
         return False
 
+    def _update_repo_with_pushlock(self):
+        lockfile = None
+        try:
+            lockfile = open(self._lockfile_path, 'w')
+            rc = fcntl.flock(lockfile, fcntl.LOCK_EX)
+        except IOError, (errno, strerr):
+            print "Repo Error (%s): opening lockfile %s failed.  Output: (errno %d) '%s'" % (target_string, self._lockfile_path, errno, strerr)
+
+        try:
+            self._update_repo()
+        except:
+            if lockfile:
+                fcntl.flock(lockfile, fcntl.LOCK_UN)
+                lockfile.close()
+            raise
+        if lockfile:
+            fcntl.flock(lockfile, fcntl.LOCK_UN)
+            lockfile.close()
+
     def _update_repo(self):
         """ Copy new RPMS to each repo, and update each repo at the end """
+        target_string = self._target_cfg.target_string()
+
         for buildjob in self._repo_additions:
             # Ensure all the files are accessible
             success = True
@@ -97,6 +122,9 @@
                 if not os.path.exists(src) or not os.access(src, os.R_OK):
                     success = False
                     bad_file = src
+                    print "Repo: %s is inaccessible." % src
+                else:
+                    print "Repo: %s is accessible." % src
 
             if success:
                 for src in buildjob.repofiles.keys():
@@ -199,7 +229,12 @@
             if self._lock_count == 2:
                 target_str = self._target_cfg.target_string()
                 print "Repo '%s': updating repository metadata..." % target_str
-                self._update_repo()
+                try:
+                    self._update_repo_with_pushlock()
+                except IOError, (err, strerr):
+                    print "Repo '%s': %s (%d)" % (target_str, strerr, err)
+                except OSError, e:
+                    print "Repo '%s': %s" % (target_str, e)
                 print "Repo '%s': Done updating." % target_str
 
                 # If there's a repo script for this target, enter level 3