Snix's nar-bridge[1] stores NARs under a different URL, i.e.
`nar/snix-castore/<hash>.nar` rather than `nar/<filehash>.nar`. Right
now, when copying into such a store via the http binary-cache, we'd end
up with wrong cache entries that point to the wrong NAR URL.
On Hydra, this is a fatal error, i.e. builds that depend on previously
built paths (that were written to the cache before by the queue runner)
would be aborted because of that.
This patch removes the caching since we'd have to re-fetch the narinfo
to do taht and this can also happen the next time, the narinfo is
queried. Also, removes the negative cache entry indicating that the
store-path doesn't exist in the store.
We don't have any coverage for http-stores so far, so I wrote a small
testcase for the "default" case and the nar-bridge case in functional2
since it has a very nice fixture for an HTTP server ready. I'm aware
that there's a CL for a nicer cache server[2], but given I'm down a
pretty deep rabbit hole by playing around with Snix, I decided to not
finish the CL and write something small for the tests in here. This can
be replaced by the fixtures from that CL later on as well.
[1] https://snix.dev/docs/components/overview/#nar-bridge
[2] https://gerrit.lix.systems/c/lix/+/2431/1
Change-Id: I4fcdf47a6bf9c3c8fbeb235eeca7a48914a4d693
Maximilian Bosch
f077a6f36e