improve the error messages when invalid declarative jobsets are defined

Dependencies

• [2] 6WRGCITD Enable declarative projects.
• [3] VHV6GI4L Add a jobset eval action to restart all aborted/cancelled builds
• [4] CHI2EHBJ declarative projects: Pull jobset spec build from the remote store
• [*] OOQ2D3KC * Refactoring: move fetchInput out of hydra_scheduler into a separate

Change contents

• replacement in src/lib/Hydra/Helper/AddBuilds.pm at line 79
  [2.2627]→[2.2627:2703](∅→∅)
  − updateDeclarativeJobset($db, $project, $jobsetName, $spec);
  [2.2627]

  [2.2703]
  + eval {

  + updateDeclarativeJobset($db, $project, $jobsetName, $spec);

  + };

  + if ($@) {

  + print STDERR "ERROR: failed to process declarative jobset ", $project->name, ":${jobsetName}, ", $@, "\n";

  + }