With esr52 Trac says it is reading and transferring bytes (seemingly endlessly)
Creating tickets or modifying them with e10s enabled often results in an endlessly spinning icon on the tab and on the the bottom of the page one can read "Transferring data from trac.torproject.org..." or "Read trac.torproject.org". I am not sure but I think there are no bytes transferred/sent. I feel there is just connection weirdness going on.
This change e.g. if I go to Trac in a new tab. Suddenly the icon on the former tab stops spinning and all is fine. This happens at least with a 64bit Linux.
(Sorry for the vague bug report :) )