From fea969e91b4a90a88e7a4a75ea2dfef32e103d8c Mon Sep 17 00:00:00 2001
From: Mike McLean <mikem@redhat.com>
Date: Dec 05 2018 03:53:52 +0000
Subject: kojira: avoid race condition that causes "unknown task" errors


---

diff --git a/util/kojira b/util/kojira
index d9543ac..8bab3e0 100755
--- a/util/kojira
+++ b/util/kojira
@@ -201,6 +201,7 @@ class RepoManager(object):
         self._local.session = session
         self.repos = {}
         self.tasks = {}
+        self.recent_tasks = {}
         self.other_tasks = {}
         self.needed_tags = {}
         self.tag_use_stats = {}
@@ -533,6 +534,13 @@ class RepoManager(object):
         - check for other newRepo tasks (not generated by us)
         """
 
+        # prune recent tasks
+        now = time.time()
+        for task_id in self.recent_tasks:
+            if now - self.recent_tasks[task_id] > 600:
+                del self.recent_tasks[task_id]
+
+        # check on current tasks
         task_ids = list(self.tasks)
         self.session.multicall = True
         for task_id in task_ids:
@@ -542,9 +550,11 @@ class RepoManager(object):
             tag_id = self.tasks[task_id]['tag_id']
             if tstate == 'CLOSED':
                 self.logger.info("Finished: newRepo task %s for tag %s" % (task_id, tag_id))
+                self.recent_tasks[task_id] = time.time()
                 del self.tasks[task_id]
             elif tstate in ('CANCELED', 'FAILED'):
                 self.logger.info("Problem: newRepo task %s for tag %s is %s" % (task_id, tag_id, tstate))
+                self.recent_tasks[task_id] = time.time()
                 del self.tasks[task_id]
             else:
                 self.tasks[task_id]['taskinfo'] = tinfo
@@ -676,10 +686,14 @@ class RepoManager(object):
                 if task_id in self.tasks:
                     # we already have a task
                     continue
+                elif task_id in self.recent_tasks:
+                    # avoiding a race, see https://pagure.io/koji/issue/942
+                    continue
                 else:
                     # should not happen
                     logger.warning('Needed tag refers to unknown task. '
                             '%s -> %i', tagname, task_id)
+                    # we'll advance and create a new task
             taskopts = {}
             if koji.util.multi_fnmatch(tagname, debuginfo_pat):
                 taskopts['debuginfo'] = True