diff -r 52f8b07ad2f9 -r d56a2d6f34f0 mercurial/localrepo.py
--- a/mercurial/localrepo.py	Sat Jan 18 10:37:14 2020 -0800
+++ b/mercurial/localrepo.py	Tue Jan 07 11:24:05 2020 +0100
@@ -676,6 +676,8 @@
     configs are loaded. For example, an extension may wish to pull in
     configs from alternate files or sources.
     """
+    if b'HGRCSKIPREPO' in encoding.environ:
+        return False
     try:
         ui.readconfig(hgvfs.join(b'hgrc'), root=wdirvfs.base)
         return True