We now keep *all* unfinished evaluations of a jobset, in addition to
the <keepnr> most recent finished evaluations.
The main motivation is to ensure that mirror-{nixos,nixpkgs} work
properly: if building an evaluation takes too long, some of its builds
may already have been garbage-collected by the time the others finish.
We had Postgres barfing with this error:
DBIx::Class::Storage::DBI::_dbh_execute(): DBI Exception: DBD::Pg::st execute failed: ERROR: stack depth limit exceeded
because the ‘drvpath => [ @dependentDrvs ]’ in failDependents can
cause a query of unbounded size. (In this specific case there was a
failure of Bison, which has > 10000 dependent derivations.) So now we
just get all scheduled builds from the DB.
Due to the fixed-output derivation hashing scheme, there can be
multiple derivations of the same output path. But build logs are
indexed by derivation path. Thus, we may not be able to find the
log of a build or build step using its derivation. So as a fallback,
Hydra now looks for other derivations with the same output paths.
They're mostly redundant since there is a faster "jobs" tab on
the jobset pages now. The only thing the latter lacks is the
ability to see status change times, but those are quite expensive
to compute, and are visible on build pages if you really need them.
PostgreSQL and Perl have different sort orders, in particular when
comparing job names such as "aspell.x86_64-linux" and
"aspellDicts.cs.i686-freebsd". This confused the evaluation
comparison code, causing some jobs to appear as "removed".
So now we do all the sorting in Perl.
Fixes#105.
Aggregate constituents are derivations. However there can be multiple
builds in an evaluation that have the same derivation, i.e. they can
alias each other (e.g. "emacs", "emacs24" and "emacs24Packages.emacs"
in Nixpkgs). Previously we picked a build arbitrarily for the
AggregateConstituents table. Now we pick the one with the shortest
name (e.g. "emacs").
On 32-bit, Linux 3.4, and if the memory size is bigger than a certain
value, starting the stage 2 init script fails with "Exec format error"
because the 9P filesystem is returning garbage. No such problem with
Linux 3.10.
http://hydra.nixos.org/build/5737226
