Here is how this changes the HSv3 client-side and service-side:
For service side we already required live consensus to upload descriptors (see
9e900d1db7) so we should never get there without
a live consensus.
For the client-side we now require a live consensus to attempt to connect to
HS. While this changes the client behavior in principle, it doesn't really
change it, because we always required live consensus to set HSDir indices, so
before this patch a client with no live consensus would try to compute
responsible HSDirs without any HSDir indices and bug out. This makes the client
behavior more consistent, by requiring a live consensus (and hence a
semi-synced clock) for the client to connect to an HS entirely.
The alternative would have been to allow setting HSDir indices with a non-live
consensus, but this would cause the various problems outlined by commit
b89d2fa1db.
There are a few reasons that relays might be uploading desciptors
without saying X-Desc-Gen-Reason:
1. They are running an old version of our software, before 0.3.2.stable.
2. They are not running our software, but they are claiming they
are.
3. They are uploading through a proxy that strips X-Desc-Gen-Reason.
4. They somehow had a bug in their software.
According to the 25686 data, 1 is the most common reason. This
ticket is an attempt to diagnose case 4, or prove that case 4
doesn't actually happen.
Note that clippy is quite loud/obnoxious, as its name would imply.
This target isn't meant to run on CI, or even necessarily exit
cleanly. It's merely a way for developers to check if they've made
any glaring mistakes, or done awkward things they might not have
otherwise realised. We *can* configure it to be quieter in the
future, but it's probably not worth rabbitholing on.
* CLOSES#22156: https://bugs.torproject.org/22156