diff -r 2cdf47e14c30 -r 1f7d9024674c mercurial/hgweb/hgwebdir_mod.py
--- a/mercurial/hgweb/hgwebdir_mod.py	Sat Mar 10 11:03:45 2018 -0800
+++ b/mercurial/hgweb/hgwebdir_mod.py	Sat Mar 10 10:56:10 2018 -0800
@@ -287,6 +287,11 @@
                 real = repos.get(virtualrepo)
                 if real:
                     wsgireq.env['REPO_NAME'] = virtualrepo
+                    # We have to re-parse because of updated environment
+                    # variable.
+                    # TODO this is kind of hacky and we should have a better
+                    # way of doing this than with REPO_NAME side-effects.
+                    wsgireq.req = requestmod.parserequestfromenv(wsgireq.env)
                     try:
                         # ensure caller gets private copy of ui
                         repo = hg.repository(self.ui.copy(), real)