We have a few extensions, hooks and other settings that need to be configured for all of our Hg repos. To save the headache of configuring every one of these individually, we configure these in the global config file /etc/mercurial/hgrc.
Since the fix for issue
#970, the global config file, and almost every other configuration file, is ignored. As a result, our global settings are no longer being applied in 1.60.