--- a/hgext/bundleclone/__init__.py
+++ b/hgext/bundleclone/__init__.py
@@ -189,17 +189,17 @@ import mercurial.wireproto as wireproto
 
 demandimport.disable()
 try:
     from mercurial import exchange
 except ImportError:
     exchange = None
 demandimport.enable()
 
-testedwith = '2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6'
+testedwith = '2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9'
 buglink = 'https://bugzilla.mozilla.org/enter_bug.cgi?product=Developer%20Services&component=Mercurial%3A%20bundleclone'
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 
 origcapabilities = wireproto.capabilities
 
 

--- a/hgext/bzexport/__init__.py
+++ b/hgext/bzexport/__init__.py
@@ -57,17 +57,18 @@ from hgext import mq
 
 OUR_DIR = os.path.dirname(__file__)
 execfile(os.path.join(OUR_DIR, '..', 'bootstrap.py'))
 
 import bzauth
 import bz
 from mozautomation.commitparser import BUG_RE
 
-testedwith = '3.4 3.5 3.6 3.7'
+testedwith = '3.6 3.7 3.8 3.9'
+minimumhgversion = '3.6'
 buglink = 'https://bugzilla.mozilla.org/enter_bug.cgi?product=Developer%20Services&component=Mercurial%3A%20bzexport'
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 
 review_re = re.compile(r'[ra][=?]+(\w[^ ]+)')
 
 BINARY_CACHE_FILENAME = ".bzexport.cache"

--- a/hgext/bzpost/__init__.py
+++ b/hgext/bzpost/__init__.py
@@ -70,17 +70,17 @@ execfile(os.path.join(OUR_DIR, '..', 'bo
 # requests doesn't like lazy module loading.
 demandimport.disable()
 from bugsy import Bugsy
 demandimport.enable()
 from mozautomation.commitparser import parse_bugs
 from mozautomation import repository
 from mozhg.auth import getbugzillaauth
 
-testedwith = '3.1 3.2 3.3 3.4 3.5 3.6'
+testedwith = '3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9'
 buglink = 'https://bugzilla.mozilla.org/enter_bug.cgi?product=Developer%20Services&component=Mercurial%3A%20bzpost'
 
 
 def wrappedpushbookmark(orig, pushop):
     result = orig(pushop)
 
     # pushop.ret was renamed to pushop.cgresult in Mercurial 3.2. We can drop
     # this branch once we drop <3.2 support.

--- a/hgext/checkpystyle/__init__.py
+++ b/hgext/checkpystyle/__init__.py
@@ -5,17 +5,18 @@ from __future__ import absolute_import
 
 import os
 
 from mercurial import demandimport
 
 OUR_DIR = os.path.dirname(__file__)
 execfile(os.path.join(OUR_DIR, '..', 'bootstrap.py'))
 
-testedwith = '3.5 3.6'
+testedwith = '3.6 3.7 3.8 3.9'
+minimumhgversion = '3.6'
 
 def critique(ui, repo, entire=False, node=None, **kwargs):
     """Perform a critique of a changeset."""
     # We run into weird import issues when running static analysis if the
     # demandimporter is enabled.
     with demandimport.deactivated():
         from flake8.engine import get_style_guide
         from pep8 import DiffReport, parse_udiff

--- a/hgext/configwizard/__init__.py
+++ b/hgext/configwizard/__init__.py
@@ -270,17 +270,17 @@ Your hgrc file is currently readable by 
 
 Sensitive information such as your Bugzilla credentials could be
 stolen if others have access to this file/machine.
 
 Would you like to fix the file permissions (Yn) $$ &Yes $$ &No
 '''.strip()
 
 
-testedwith = '3.5 3.6 3.7 3.8'
+testedwith = '3.6 3.7 3.8 3.9'
 buglink = 'https://bugzilla.mozilla.org/enter_bug.cgi?product=Developer%20Services&component=Mercurial%3A%20configwizard'
 
 cmdtable = {}
 
 # We want the extension to load on ancient versions of Mercurial.
 # cmdutil.command was introduced in 1.9.
 try:
     command = cmdutil.command(cmdtable)

--- a/hgext/firefoxtree/__init__.py
+++ b/hgext/firefoxtree/__init__.py
@@ -102,18 +102,18 @@ execfile(os.path.join(OUR_DIR, '..', 'bo
 
 from mozautomation.repository import (
     MULTI_TREE_ALIASES,
     resolve_trees_to_uris,
     resolve_uri_to_tree,
     TRY_TREES,
 )
 
-testedwith = '3.5 3.6 3.7 3.8'
-minimumhgversion = '3.5'
+testedwith = '3.6 3.7 3.8 3.9'
+minimumhgversion = '3.6'
 buglink = 'https://bugzilla.mozilla.org/enter_bug.cgi?product=Developer%20Services&component=Mercurial%3A%20firefoxtree'
 # The root revisions in mozilla-central and comm-central, respectively.
 MOZ_ROOT_REV = '8ba995b74e18334ab3707f27e9eb8f4e37ba3d29'
 COMM_ROOT_REV = 'e4f4569d451a5e0d12a6aa33ebd916f979dd8faa'
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 

--- a/hgext/hgmo/__init__.py
+++ b/hgext/hgmo/__init__.py
@@ -100,18 +100,18 @@ from mercurial.hgweb.protocol import (
 OUR_DIR = os.path.dirname(__file__)
 ROOT = os.path.normpath(os.path.join(OUR_DIR, '..', '..'))
 execfile(os.path.join(OUR_DIR, '..', 'bootstrap.py'))
 
 import mozautomation.commitparser as commitparser
 import mozhg.mozbuildinfo as mozbuildinfo
 
 
-minimumhgversion = '3.8'
-testedwith = '3.8'
+minimumhgversion = '3.9'
+testedwith = '3.9'
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 
 
 def addmetadata(repo, ctx, d, onlycheap=False):
     """Add changeset metadata for hgweb templates."""
     description = encoding.fromlocal(ctx.description())

--- a/hgext/mozext/__init__.py
+++ b/hgext/mozext/__init__.py
@@ -338,17 +338,18 @@ try:
         TREE_ALIASES,
     )
 finally:
     if demandenabled:
         demandimport.enable()
 
 bz_available = False
 
-testedwith = '3.4 3.5 3.6 3.7'
+testedwith = '3.6 3.7 3.8 3.9'
+minimumhgversion = '3.6'
 buglink = 'https://bugzilla.mozilla.org/enter_bug.cgi?product=Developer%20Services&component=Mercurial%3A%20mozext'
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 
 colortable = {
     'buildstatus.success': 'green',
     'buildstatus.failed': 'red',

--- a/hgext/mqext/__init__.py
+++ b/hgext/mqext/__init__.py
@@ -70,17 +70,17 @@ Alternatively, if you only want a subset
 the -Q option to all relevant commands in your ~/.hgrc::
 
   [defaults]
   qnew = -Q
   qdelete = -Q
   qimport = -Q
 '''
 
-testedwith = '3.4 3.5 3.6 3.7'
+testedwith = '3.6 3.7 3.8 3.9'
 
 import os
 import re
 import json
 import urllib2
 
 from mercurial.i18n import _
 from mercurial.node import short

--- a/hgext/obsolescencehacks/__init__.py
+++ b/hgext/obsolescencehacks/__init__.py
@@ -6,18 +6,18 @@
 import os
 import pwd
 
 from mercurial import (
     error,
     obsolete,
 )
 
-testedwith = '3.7'
-minimumhgversion = '3.7'
+testedwith = '3.9'
+minimumhgversion = '3.9'
 
 
 def enableevolutionexchange(repo):
     """Enable obsolescence markers exchange if conditions are met."""
     ui = repo.ui
 
     # Nothing to do if obsolescence isn't enabled at all.
     opts = (obsolete.createmarkersopt, obsolete.allowunstableopt, obsolete.exchangeopt)

--- a/hgext/push-to-try/__init__.py
+++ b/hgext/push-to-try/__init__.py
@@ -9,17 +9,17 @@ from mercurial.i18n import _
 OUR_DIR = os.path.normpath(os.path.dirname(__file__))
 execfile(os.path.join(OUR_DIR, '..', 'bootstrap.py'))
 
 from mozhg.rewrite import preservefilectx
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 
-testedwith = '3.3 3.4 3.5 3.6'
+testedwith = '3.6 3.7 3.8 3.9'
 
 @command('push-to-try', [
     ('m', 'message', '', 'commit message to use', 'MESSAGE'),
     ('s', 'server', 'ssh://hg.mozilla.org/try', 'push destination', 'URL'),
 ], '-m MESSAGE -s URL')
 def push_to_try(ui, repo, server, message=None):
 
     nodate = ui.configbool('push-to-try', 'nodate')

--- a/hgext/qbackout/__init__.py
+++ b/hgext/qbackout/__init__.py
@@ -21,17 +21,17 @@ execfile(os.path.join(OUR_DIR, '..', 'bo
 from mozautomation.commitparser import BUG_RE
 # mercurial version portability
 import sys
 if not getattr(cmdutil, 'bailifchanged', None):
     cmdutil.bailifchanged = cmdutil.bail_if_changed
 if 'mercurial.scmutil' not in sys.modules:
     import mercurial.cmdutil as scmutil
 
-testedwith = '3.4 3.5 3.6 3.7'
+testedwith = '3.6 3.7 3.8 3.9'
 buglink = 'https://bugzilla.mozilla.org/enter_bug.cgi?product=Developer%20Services&component=Mercurial%3A%20qbackout'
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 
 backout_re = re.compile(r'[bB]ack(?:ed)?(?: ?out) (?:(?:changeset|revision|rev) )?([a-fA-F0-9]{8,40})')
 reapply_re = re.compile(r'Reapplied (?:(?:changeset|revision|rev) )?([a-fA-F0-9]{8,40})')
 

--- a/hgext/qimportbz/__init__.py
+++ b/hgext/qimportbz/__init__.py
@@ -41,17 +41,18 @@ import os
 import urllib
 
 import bz
 import bzhandler
 import pb
 import scp
 
 buglink = 'https://bugzilla.mozilla.org/enter_bug.cgi?product=Developer%20Services&component=Mercurial%3A%20qimportbz'
-testedwith = '3.3 3.4 3.5 3.6'
+testedwith = '3.6 3.7 3.8 3.9'
+minimumhgversion = '3.6'
 
 
 def extsetup(ui):
     # Insert preview flag into qimport
     qimport_cmd = cmdutil.findcmd("qimport", mq.cmdtable)
     cmdtable = mq.cmdtable
     qimport_cmd[1][1].append(('p', 'preview', False, "preview commit message"))
 

--- a/hgext/readonly/__init__.py
+++ b/hgext/readonly/__init__.py
@@ -16,17 +16,18 @@ can be set in your global hgrc to allow 
 as read only.
 '''
 
 import errno
 
 from mercurial.i18n import _
 from mercurial import util
 
-testedwith = '3.5 3.6'
+testedwith = '3.6 3.7 3.8 3.9'
+minimumhgversion = '3.6'
 buglink = 'https://bugzilla.mozilla.org/enter_bug.cgi?product=Developer%20Services&component=Mercurial%3A%20hg.mozilla.org'
 
 def prechangegrouphook(ui, repo, **kwargs):
     return checkreadonly(ui, repo, 'add changesets')
 
 
 def prepushkeyhook(ui, repo, namespace=None, **kwargs):
     return checkreadonly(ui, repo, 'update %s' % namespace)

--- a/hgext/reviewboard/client.py
+++ b/hgext/reviewboard/client.py
@@ -77,17 +77,18 @@ from mozhg.auth import (
     getbugzillaauth,
     configureautobmoapikeyauth,
 )
 from mozhg.rewrite import (
     newparents,
     replacechangesets,
 )
 
-testedwith = '3.3 3.4 3.5 3.6'
+testedwith = '3.6 3.7 3.8 3.9'
+minimumhgversion = '3.6'
 buglink = 'https://bugzilla.mozilla.org/enter_bug.cgi?product=MozReview&component=Integration%3A%20Mercurial'
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 
 
 clientcapabilities = {
     'proto1',

--- a/hgext/reviewboard/server.py
+++ b/hgext/reviewboard/server.py
@@ -51,17 +51,18 @@ execfile(os.path.join(OUR_DIR, '..', 'bo
 
 with demandimport.deactivated():
     try:
         import hgrb.proto
     except ImportError:
         sys.path.insert(0, OUR_DIR)
         import hgrb.proto
 
-testedwith = '3.3 3.4 3.5 3.6'
+testedwith = '3.9'
+minimumhgversion = '3.9'
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 
 
 # Capabilities the server requires in clients.
 #
 # Add to this and add a corresponding entry in the client extension to force

--- a/hgext/robustcheckout/__init__.py
+++ b/hgext/robustcheckout/__init__.py
@@ -25,17 +25,17 @@ from mercurial import (
     exchange,
     extensions,
     cmdutil,
     hg,
     scmutil,
     util,
 )
 
-testedwith = '3.5 3.6 3.7 3.8'
+testedwith = '3.6 3.7 3.8 3.9'
 minimumhgversion = '3.7'
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 
 
 if os.name == 'nt':
     import ctypes

--- a/hgext/serverlog/__init__.py
+++ b/hgext/serverlog/__init__.py
@@ -179,17 +179,17 @@ from mercurial import (
     wireproto,
 )
 from mercurial.hgweb import (
     protocol,
     hgweb_mod,
     hgwebdir_mod,
 )
 
-testedwith = '3.6 3.7'
+testedwith = '3.6 3.7 3.8 3.9'
 minimumhgversion = '3.6'
 
 origcall = protocol.call
 
 def protocolcall(repo, req, cmd):
     """Wraps mercurial.hgweb.protocol to record requests."""
 
     # TODO figure out why our custom attribute is getting lost in