pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-2378-Lamb_Skinnet.ps) >>/Users/jc/w/tmp/Tune-2378-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/LM/Lamb_Skinnet.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Coll_2378.log 471011 Log file, useful mostly for debugging
Coll_23780.log 273610 Log file, useful mostly for debugging
Coll_23781.log 473808 Log file, useful mostly for debugging
Coll_23784.log 737619 Log file, useful mostly for debugging
Form_23785.log 1476 Log file, useful mostly for debugging
Form_23789.log 1021 Log file, useful mostly for debugging
Tune-2378-Lamb_Skinnet.abc 917 ABC music file with the extracted tune(s)
Tune-2378-Lamb_Skinnet.ps 35363 PostScript
Tune-2378-Lamb_Skinnet.txt 917 Plain-text file with the extracted tune(s)
Tune-2378-get.log 15560 Log file, useful mostly for debugging
Tune-23780-get.log 8068 Log file, useful mostly for debugging
Tune-23781-get.log 177742 Log file, useful mostly for debugging
Tune-23782-get.log 178428 Log file, useful mostly for debugging
Tune-23783-get.log 4920 Log file, useful mostly for debugging
Tune-23787-get.log 4544 Log file, useful mostly for debugging
Tune-23788-get.log 2928 Log file, useful mostly for debugging
Tune-23789-get.log 7141 Log file, useful mostly for debugging
These files should be available for 24 hours.