Latexmk: Summary of warnings:
  Latex failed to resolve 1 reference(s)
  Latex failed to resolve 2 citation(s)
Collected error summary (may duplicate other messages):
Latexmk: Errors, so I did not complete making targets
  pdflatex: Command for 'pdflatex' gave return code 256
Latexmk: Use the -f option to force complete processing,
 unless error was exceeding maximum runs of latex/pdflatex.
ERROR: Job failed: exit code 1