Make the output less chatty

2 jobs for master in 27 minutes and 36 seconds (queued for 20 seconds)
Name Stage Failure
failed
Typeset example documents Build
  Latex failed to resolve 2 citation(s)
Collected error summary (may duplicate other messages):
pdflatex: Command for 'pdflatex' gave return code 1
Refer to 'muzeu-slovak.log' for details
Latexmk: Use the -f option to force complete processing,
unless error was exceeding maximum runs, or warnings treated as errors.
xargs: sh: exited with status 255; aborting
Cleaning up file based variables
ERROR: Job failed: exit code 1