diff -r 303dae0136b0 -r 8da20fc9fc07 hgext/fastannotate/protocol.py
--- a/hgext/fastannotate/protocol.py	Thu Aug 09 15:05:43 2018 -0400
+++ b/hgext/fastannotate/protocol.py	Thu Aug 09 15:08:32 2018 -0400
@@ -223,5 +223,7 @@
     _registerwireprotocommand()
     if isinstance(repo, localrepo.localrepository):
         localreposetup(ui, repo)
+    # TODO: this mutates global state, but only if at least one repo
+    # has the extension enabled. This is probably bad for hgweb.
     if peersetup not in hg.wirepeersetupfuncs:
         hg.wirepeersetupfuncs.append(peersetup)