Implement threading for breakage messages.

master.cfg

@@ -219,6 +219,62 @@ def SendRootMessageGDBTesters (branch, change, rev,
 def make_breakage_lockfile_name (branch, builder):
     return "/tmp/gdb-buildbot-breakage-report-%s-%s" % (branch, builder)
 
+def make_breakage_root_message_id_filename (rev, branch):
+    return "/tmp/gdb-buildbot-message-id-breakage-%s-%s" % (rev, branch)
+
+def make_breakage_root_message_id (rev, branch):
+    mid_file = make_breakage_root_message_id_filename (rev, branch)
+    mid = "%s-%s-breakage@gdb-build" % (rev, branch)
+    if not os.path.exists (mid_file):
+        mf = open (mid_file, 'w')
+        mf.write (mid)
+        mf.close ()
+    return mid
+
+def SendRootBreakageMessage (builder, branch, change):
+    """Send the root message that will contain the breakage emails."""
+    global GDB_MAIL_FROM
+
+    rev = change.revision
+
+    if os.path.exists (make_breakage_root_message_id_filename (rev, branch)):
+        # Already sent
+        return
+
+    message_id = make_breakage_root_message_id (rev, branch)
+    to = change.who.encode ('ascii', 'ignore').decode ('ascii')
+    to += ", gdb-patches@sourceware.org"
+    to_list = [ to ]
+    to_list.append ('gdb-patches@sourceware.org')
+    title = change.comments.split ('\n')[0]
+
+    sbj = 'Oh dear.  I regret to inform you that commit %s might be unfortunate' % change.revision
+    if branch != 'master':
+        sbj += ' [%s]' % branch
+
+    text = "My lords, ladies, gentlemen, members of the public.\n\n"
+    text += "It is a matter of great regret and sadness to inform you that commit:\n\n"
+    text += "\t%s\n" % title
+    text += "\t%s\n\n" % rev
+    text += "might have made GDB unwell.  Since I am just your Butler BuildBot,\n"
+    text += "I kindly ask that a human superior officer double-check this.\n\n"
+    text += "Please note that if you are reading this message on gdb-patches, there might\n"
+    text += "be other builders broken.\n\n"
+    text += "You can find more details about the unfortunate breakage in the next messages.\n\n"
+    text += "Cheers,\n\n"
+    text += "Your GDB BuildBot."
+
+    mail = MIMEText (text)
+    mail['Subject'] = sbj
+    mail['From'] = 'gdb-buildbot@sergiodj.net'
+    mail['To'] = to
+    mail['Message-Id'] = message_id
+
+    s = smtplib.SMTP ('localhost')
+    s.sendmail (GDB_MAIL_FROM, to_list, mail.as_string ())
+    s.quit ()
+
+
 def SendAuthorBreakageMessage (name, branch, change, text_prepend):
     """Send a message to the author of the commit if it broke GDB.
 
@@ -237,39 +293,35 @@ subsequent commits are made after X, by different people."""
     # This file will be cleaned the next time we run
     # MessageGDBTesters, iff the build breakage has been fixed.
     bf = open (lockfile, 'w')
-    bf.write ("Commit that caused the breakage: %s\n" % change.revision)
+    bf.write ("Commit: %s\n" % change.revision)
     bf.close ()
 
+    SendRootBreakageMessage (name, branch, change)
+    root_message_id = make_breakage_root_message_id (rev, branch)
+
     rev = change.revision
     to = change.who.encode ('ascii', 'ignore').decode ('ascii')
+    to += ", gdb-patches@sourceware.org"
     to_list = [ to ]
+    to_list.append ('gdb-patches@sourceware.org')
     title = change.comments.split ('\n')[0]
 
-    sbj = 'Oh dear.  I regret to inform you that commit %s might be unfortunate' % change.revision
+    sbj = 'Breakage on builder %s, revision %s' % (name, rev)
     if branch != 'master':
         sbj += ' [%s]' % branch
 
-    text = "My lords, ladies, gentlemen, members of the public.\n\n"
-    text += "It is a matter of great regret and sadness to inform you that commit:\n\n"
-    text += "\t%s\n" % title
-    text += "\t%s\n\n" % rev
-    text += "might have made GDB unwell.  Since I am just your Butler BuildBot,\n"
-    text += "I kindly ask that a human superior officer double-check this.\n\n"
-    text += "Please note that if you are reading this message on gdb-patches, there might\n"
-    text += "be other builders broken.\n\n"
-    text += "You can find more details about the unfortunate breakage below.\n\n"
-    text += "Cheers,\n\n"
-    text += "Your GDB BuildBot.\n\n"
+    text += "Unfortunately it seems that there is a breakage on GDB.\n\n"
+    text += "Commit title: '%s'\n" % title
+    text += "Revision: %s\n\n" %rev
+    text += "You can find more details below:\n\n"
     text += "+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\n\n"
-    text += "\n" + text_prepend
+    text += text_prepend
 
     mail = MIMEText (text)
     mail['Subject'] = sbj
     mail['From'] = 'gdb-buildbot@sergiodj.net'
-    to += ", gdb-patches@sourceware.org"
-    to_list.append ('gdb-patches@sourceware.org')
     mail['To'] = to
-    mail['Reply-To'] = 'gdb-patches@sourceware.org'
+    mail['In-Reply-To'] = root_message_id
 
     s = smtplib.SMTP ('localhost')
     s.sendmail (GDB_MAIL_FROM, to_list, mail.as_string ())
@@ -428,9 +480,15 @@ send to the gdb-testers mailing list."""
         # There is no build breakage anymore!  Yay!  Now, let's see if
         # we need to clean up any lock file from previous breaks.
         lockfile = make_breakage_lockfile_name (branch, name)
+        with open (lockfile, 'r') as f:
+            rev_broke = f.readline ().lstrip ("Commit: ")
+        mid_file = make_breakage_root_message_id_filename (rev_broke, branch)
         if os.path.exists (lockfile):
             # We need to clean the lockfile.  Garbage-collect it here.
             os.remove (lockfile)
+        if os.path.exists (mid_file):
+            # Garbage-collect the Message-Id file
+            os.remove (mid_file)
 
     return { 'body' : text,
              'type' : 'plain',