Inconsistent failure-then-success bootstrap behavior with clock set 24h in the past
Context: I'm investigating which part of Tails' crazy clock fixing dance we can remove thanks to https://trac.torproject.org/projects/tor/ticket/24661. Corresponding Tails ticket: https://redmine.tails.boum.org/code/issues/16471.
Environment: Tor Browser 9.0.1 x86_64 on Debian unstable, clock set 24h before UTC. Tested both with direct connection to the Tor network and with bridges.
The first time I click "Connect" in Tor Launcher, I see a bootstrapping error (see attached screenshot and Tor logs):
Tor failed to establish a Tor network connection. Loading authority certificates failed (Clock skew -81944 in microdesc flavor consensus from CONSENSUS - ?).
I guess that's kind of expected despite the improvements implemented as part of https://trac.torproject.org/projects/tor/ticket/24661.
But then, if I click "Reconfigure" and then "Connect", tor bootstraps successfully. This surprises me and feels inconsistent: the way I see it, either the clock is skewed enough for tor to fail bootstrapping, and then it should not succeed on second try; or tor can somehow deal with skewed clock, and then it should succeed on first try.