Ihor Radchenko writes: > Thanks! You're welcome. > It looks like ob-lilypond/ly-compile-lilyfile test is relying on > this > optional second argument. So, after applying your patch, make > test is > failing. I've amended the test using cl-letf. I also bound the variables which may generate output files to nil to prevent generating any output files if the test is run interactively. See attached.