Make evaluation fail with proper error when a input of type build is not available.

Dependencies

• [2] SS4TZXNU Distinguish between permanent evaluation errors and transient input errors
• [3] OOQ2D3KC * Refactoring: move fetchInput out of hydra_scheduler into a separate
• [4] KQS7DSKJ * Clean up indentation.
• [5] X5EOJLNA Allow passing a specific build as an input
• [6] PMNWRTGJ Add multiple output support

Change contents

• replacement in src/lib/Hydra/Helper/AddBuilds.pm at line 98
  [3.9288]→[2.0:87](∅→∅)
  − return () if !defined $prevBuild || !isValidPath(getMainOutput($prevBuild)->path);
  [3.9288]

  [3.9475]
  + die "Input $name: No builds available at $value" if !defined $prevBuild || !isValidPath(getMainOutput($prevBuild)->path);