This is needed to make Mercurial read the HGEXTENSIONPATH to detect
third-party extensions.  It is called HGEXTENSIONPATH and not
HG_EXTENSION_PATH to keep it consistent with other environment variables for
Mercurial, e.g. HGENCODINGAMBIGUOUS, HGEDITOR ...  Hopefully I or someone else
will get this into Mercurial proper.

diff --git a/mercurial/extensions.py b/mercurial/extensions.py
--- a/mercurial/extensions.py
+++ b/mercurial/extensions.py
@@ -13,6 +13,7 @@
 import imp
 import inspect
 import os
+import sys
 
 from .i18n import (
     _,
@@ -108,6 +109,11 @@
 
 def _importh(name):
     """import and return the <name> module"""
+    # Read HGEXTENSIONSPATH environment variable when import extensions.
+    extension_path = os.getenv("HGEXTENSIONSPATH")
+    if extension_path is not None:
+        for path in extension_path:
+            sys.path.append(path)
     mod = __import__(pycompat.sysstr(name))
     components = name.split(b'.')
     for comp in components[1:]:
>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=b8ff50d06fd443229644ad45c69d15d928cc8d86'>refs</a><a class='active' href='/guix/log/gnu/installer/dump.scm'>log</a><a href='/guix/tree/gnu/installer/dump.scm?id=b8ff50d06fd443229644ad45c69d15d928cc8d86'>tree</a><a href='/guix/commit/gnu/installer/dump.scm?id=b8ff50d06fd443229644ad45c69d15d928cc8d86'>commit</a><a href='/guix/diff/gnu/installer/dump.scm?id=b8ff50d06fd443229644ad45c69d15d928cc8d86'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/installer/dump.scm'>
<input type='hidden' name='id' value='b8ff50d06fd443229644ad45c69d15d928cc8d86'/><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=b8ff50d06fd443229644ad45c69d15d928cc8d86'>root</a>/<a href='/guix/log/gnu?id=b8ff50d06fd443229644ad45c69d15d928cc8d86'>gnu</a>/<a href='/guix/log/gnu/installer?id=b8ff50d06fd443229644ad45c69d15d928cc8d86'>installer</a>/<a href='/guix/log/gnu/installer/dump.scm?id=b8ff50d06fd443229644ad45c69d15d928cc8d86'>dump.scm</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/gnu/installer/dump.scm?id=b8ff50d06fd443229644ad45c69d15d928cc8d86&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-11-02 15:52:19 +0100'>2022-11-02</span></td><td><a href='/guix/commit/gnu/installer/dump.scm?id=80387bc7c3966602800116f5be3893c3d3044a96'>installer: Add core dump support.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes: &lt;https://issues.guix.gnu.org/58733&gt;

* gnu/installer.scm (installer-program): Enable core dump generation.
* gnu/installer/dump.scm (%core-dump): New variable.
(prepare-dump): Copy the core dump file.
* gnu/installer/newt/welcome.scm (run-welcome-page): Propose to report an
installation that previously generated a core dump.
</span></span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2022-02-02 16:46:44 +0100'>2022-02-02</span></td><td><a href='/guix/commit/gnu/installer/dump.scm?id=ad55ccf9b18000144a4e0f28a0f9e57132f94edc'>installer: Make dump archive creation optional and selective.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/installer.scm (installer-program): Let the installer customize
the dump archive.
* gnu/installer/dump.scm (prepare-dump, make-dump): Split make-dump in
prepare-dump, which copies the files necessary for the dump, and
make-dump which creates the archive.
* gnu/installer/record.scm (installer): Add report-page field.  Change
documented return value of exit-error.
* gnu/installer/newt.scm (exit-error): Change arguments to be a string
containing the error.  Let the user choose between exiting and
initiating a dump.
(report-page): Add new variable.
* gnu/installer/newt/page.scm (run-dump-page): New variable.
* gnu/installer/newt/dump.scm: Delete it.

Signed-off-by: Mathieu Othacehe &lt;othacehe@gnu.org&gt;
</span></span></td><td>Josselin Poiret</td></tr>
<tr><td><span title='2022-02-02 16:46:42 +0100'>2022-02-02</span></td><td><a href='/guix/commit/gnu/installer/dump.scm?id=0d37a5df7e709cadca97cfbbf9c680dfe54b8302'>installer: Add crash dump upload support.</a><span class='msg-avail'>...<span class='msg-tooltip'>Suggested-by: Josselin Poiret &lt;dev@jpoiret.xyz&gt;

* gnu/installer/dump.scm: New file.
* gnu/installer/newt/dump.scm: New file.
* gnu/local.mk (INSTALLER_MODULES): Add them.
* gnu/installer/record.scm (&lt;installer&gt;)[dump-page]: New field.
* gnu/installer/steps.scm (%current-result): New variable.
(run-installer-steps): Update it.
* gnu/installer.scm (installer-program): Add tar and gip to the installer
path. Add guile-webutils and gnutls to the Guile extensions. Generate and send
the crash dump report.
* gnu/installer/newt.scm (exit-error): Add a report argument. Display the
report id.
(dump-page): New procedure.
(newt-installer): Update it.
</span></span></td><td>Mathieu Othacehe</td></tr>