incrementally ingest eval results
nix-eval-jobs streams output, unlike hydra-eval-jobs. Now that we've
migrated, we can use this to:
1. Use less RAM by avoiding buffering a whole eval's worth of metadata
into a Perl string and an array of JSON objects.
2. Make evals latency a bit lower by allowing the queue runner to start
ingesting builds faster.
Also use the newly-restored constituents support in `nix-eval-jobs`
Note, we pass --workers and --max-memory-size to n-e-j
Lost in the h-e-j -> n-e-j migration, causing evaluation to always be
single threaded and limited to 4GiB RAM. Follow the config settings like
h-e-j used to do (via C++ code).
`nix-eval-jobs` should check `hydraJobs` and then `checks` with flakes
(cherry picked from commit 6d4ccff43c41adaf6e4b2b9bced7243bc2f6e97b)
(cherry picked from commit b0e9b4b2f99f9d8f5c4e780e89f955c394b5ced4)
(cherry picked from commit cdfc5c81e8037d3e4818a3e459d0804b2c157ea9)
(cherry picked from commit 4b107e6ff36bd89958fba36e0fe0340903e7cd13)
Co-Authored-By: Maximilian Bosch <maximilian@mbosch.me>
At the moment, aggregate jobs can easily break and cause the entire
evaluation to fail, which is not ideal. For Nixpkgs, we do have some
important aggregate jobs (like `tested`), but for debugging and building
purposes it's still useful to get a partial result even if the channel
won't actually advance.
This commit changes the behaviour of hydra-eval-jobs such that it
aggregates any errors found during the construction of an aggregate, and
will instead annotate the job with the evaluation failure such that it
shows up in a "cleaner" way.
There are really two types of failure that we care about: one is where
the attribute just ends up missing altogether in the final output, and
also where the attribute is in the output but fails to evaluate. Both
are handled here.
Note that this does mean that the same error message may be output
multiple times, but this aids debuggability because it'll be much
clearer what's blocking the job from being created.
