pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-86774-2018_the_Bridge_of_Garry.ps) >>/Users/jc/w/tmp/Tune-86774-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Kerr/MM2/2018_the_Bridge_of_Garry.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Tune-86774-2018_the_Bridge_of_Garry.abc 428 ABC music file with the extracted tune(s)
Tune-86774-2018_the_Bridge_of_Garry.ps 33943 PostScript
Tune-86774-2018_the_Bridge_of_Garry.txt 428 Plain-text file with the extracted tune(s)
Tune-86774-get.log 4793 Log file, useful mostly for debugging
These files should be available for 24 hours.