When cloning a "big" (~3600 commits, 347.7 MB as indicated here) Mercurial repo I get various connection-related errors, see attached files.
My internet connection is otherwise steady and fast (120/10Mb/s) and I have no issues with anything else (including interacting with already cloned BB repos).
A few days ago I experienced similar errors on other "big" repos as well (bigger in file size at ~500MB but only 10s of commits max), from under another (even faster) internet connection. This was my first time seeing this issue. At first I thought the issue was that I was cloning to a slow storage (an SD card) but re-trying it with fast storage (various SSDs) the same issues arose multiple times.
The affected repos can be successfully cloned, but in my limited tests clone fails somehow in half, if not majority of the times.