Fix regex so that it works with Python 3.6.

See <https://docs.python.org/3/library/re.html#re.LOCALE>.

Copied from upstream bug report:
https://bugs.launchpad.net/python-mox3/+bug/1665266

From 05064cdb6ea7a16450c6beae2b6f7c6074212a69 Mon Sep 17 00:00:00 2001
From: Zac Medico <zmedico@gentoo.org>
Date: Thu, 16 Feb 2017 00:24:10 -0800
Subject: [PATCH] RegexTest: python3.6 compatibility

These fixes are backward-compatible with older python versions:

* raw strings fix invalid escape sequences
* flags=8 fixes ValueError: cannot use LOCALE flag with a str pattern
---
 mox3/tests/test_mox.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mox3/tests/test_mox.py b/mox3/tests/test_mox.py
index 15ac565..3a1af17 100644
--- a/mox3/tests/test_mox.py
+++ b/mox3/tests/test_mox.py
@@ -312,12 +312,12 @@ class RegexTest(testtools.TestCase):
     def testReprWithoutFlags(self):
         """repr should return the regular expression pattern."""
         self.assertTrue(
-            repr(mox.Regex(r"a\s+b")) == "<regular expression 'a\s+b'>")
+            repr(mox.Regex(r"a\s+b")) == r"<regular expression 'a\s+b'>")
 
     def testReprWithFlags(self):
         """repr should return the regular expression pattern and flags."""
-        self.assertTrue(repr(mox.Regex(r"a\s+b", flags=4)) ==
-                        "<regular expression 'a\s+b', flags=4>")
+        self.assertTrue(repr(mox.Regex(r"a\s+b", flags=8)) ==
+                        r"<regular expression 'a\s+b', flags=8>")
 
 
 class IsTest(testtools.TestCase):
-- 
2.10.2

hidden' name='id' value='49fa48eed78c50d9674e9868e5a2b3e029a6e403'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=49fa48eed78c50d9674e9868e5a2b3e029a6e403'>root</a>/<a href='/guix/log/CODE-OF-CONDUCT?id=49fa48eed78c50d9674e9868e5a2b3e029a6e403'>CODE-OF-CONDUCT</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/CODE-OF-CONDUCT?id=49fa48eed78c50d9674e9868e5a2b3e029a6e403&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
/div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/guix-daemon.sh?id=6d508ef6905a17d269fe53532dd5009fff77ffb6'>Collapse</a>)</th><th class='left'>Author</th></tr>
<tr class='logheader'><td><span title='2023-04-21 16:16:38 +0200'>2023-04-21</span></td><td class='logsubject'><a href='/guix/commit/tests/guix-daemon.sh?id=37dd69b44511dc73eb04bdebe8d82c9a0386338e'>tests: Fix checks for expected failures.</a></td><td>Eric Bavier</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
Addresses &lt;https://issues.guix.gnu.org/62406&gt;.

With 'set -e', a return status inverted with '!' does not cause the shell to
exit immediately.  Instead use '&amp;&amp; false' to indicate an expected failure.

* tests/guix-archive.sh, tests/guix-build-branch.sh, tests/guix-build.sh,
tests/guix-daemon.sh, tests/guix-download.sh,
tests/guix-environment-container.sh, tests/guix-environment.sh,
tests/guix-gc.sh, tests/guix-git-authenticate.sh, tests/guix-graph.sh,
tests/guix-hash.sh, tests/guix-home.sh, tests/guix-pack-relocatable.sh,
tests/guix-pack.sh, tests/guix-package-aliases.sh, tests/guix-package-net.sh,
tests/guix-package.sh, tests/guix-refresh.sh, tests/guix-shell.sh,
tests/guix-style.sh, tests/guix-system.sh: Replace uses of '! ...' with
'... &amp;&amp; false' or `test ! ...` as appropriate.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;


</td></tr>
<tr class='logheader'><td><span title='2022-10-22 01:46:55 +0200'>2022-10-22</span></td><td class='logsubject'><a href='/guix/commit/tests/guix-daemon.sh?id=a3619079f95213c4f983e69210ed12b38fd31022'>Remove now unnecessary uses of (guix grafts).</a></td><td>Ludovic Courtès</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
These modules would use (guix grafts) just to access '%graft?' and
related bindings, which are now in (guix store).

* gnu/ci.scm,
guix/gexp.scm,
guix/lint.scm,
guix/scripts.scm,
guix/scripts/archive.scm,
guix/scripts/build.scm,
guix/scripts/challenge.scm,
guix/scripts/deploy.scm,
guix/scripts/environment.scm,
guix/scripts/home.scm,
guix/scripts/pack.scm,
guix/scripts/package.scm,
guix/scripts/pull.scm,
guix/scripts/size.scm,
guix/scripts/system.scm,
guix/scripts/weather.scm,
tests/builders.scm,
tests/channels.scm,
tests/cpan.scm,
tests/derivations.scm,
tests/gexp.scm,
tests/graph.scm,
tests/guix-daemon.sh,
tests/monads.scm,
tests/pack.scm,
tests/packages.scm,
tests/profiles.scm,
tests/system.scm: Remove #:use-module (guix grafts).


</td></tr>