All successful, non-garbage-collected builds in the evaluation are
passed in a attribute set. So if you declare a Hydra input named
‘foo’ of type ‘eval’, you get a set with members ‘foo.<jobname>’. For
instance, if you passed a Nixpkgs eval as an input named ‘nixpkgs’,
then you could get the Firefox build for x86_64-linux as
‘nixpkgs.firefox.x86_64-linux’.
Inputs of type ‘eval’ can be specified in three ways:
* As the number of the evaluation.
* As a jobset identifier (‘<project>:<jobset>’), which will yield the
latest finished evaluation of that jobset. Note that there is no
guarantee that any job in that evaluation has succeeded, so it might
not be very useful.
* As a job identifier (‘<project>:<jobset>:<job>’), which will yield
the latest finished evaluation of that jobset in which <job>
succeeded. In conjunction with aggregate jobs, this allows you to
make sure that the evaluation contains the desired builds.
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.
The URI parameter "compare=..." can denote either an arbitrary
evaluation ID, or the name of a jobset in the same project. In the
latter case, the comparison is made against the latest completed
evaluation of the specified jobset.
