using latexmk

1 job for master in 54 seconds (queued for 3 seconds)
Status Name Job ID Coverage
failed compile_pdf #1620618


Name Stage Failure
compile_pdf Build
!  ==> Fatal error occurred, no output PDF file produced!
Transcript written on main-lines.log.
Collected error summary (may duplicate other messages):
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.
Latexmk: Errors, so I did not complete making targets
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1