pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-2392-Petronella.ps) >>/Users/jc/w/tmp/Tune-2392-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/abc/Scotland/program/20190906/Petronella.abc

Error exit status 256; here are some files to check:
[P=get.cgi V=1/1 B=0 scale=0.60 512x512 PNG]
filesizedescription
Coll_23929.log 142807 Log file, useful mostly for debugging
Form_23922.log 1691 Log file, useful mostly for debugging
Form_23923.log 889 Log file, useful mostly for debugging
Tune-2392-Petronella.abc 598 ABC music file with the extracted tune(s)
Tune-2392-Petronella.ps 35675 PostScript
Tune-2392-Petronella.txt 598 Plain-text file with the extracted tune(s)
Tune-2392-get.log 4719 Log file, useful mostly for debugging
Tune-23923-get.log 4081 Log file, useful mostly for debugging
These files should be available for 24 hours.