Got HTTP status 404 Not Found for "http://roaringjelly.org/~jc/music/book/Book06/Gow-CR-abc2.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-7123-Gow-CR-abc2.ps) >>/Users/jc/w/tmp/Tune-7123-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/Book06/Gow-CR-abc2.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_71234.log 284808 Log file, useful mostly for debugging
Find_71239.log 1877 Log file, useful mostly for debugging
Tune-7123-Gow-CR-abc2.abc 150 ABC music file with the extracted tune(s)
Tune-7123-Gow-CR-abc2.ps 6 PostScript
Tune-7123-Gow-CR-abc2.txt 150 Plain-text file with the extracted tune(s)
Tune-7123-get.log 4099 Log file, useful mostly for debugging
Tune-71232-get.log 1402 Log file, useful mostly for debugging
Tune-71234-get.log 4036 Log file, useful mostly for debugging
Tune-71234-newpage.abc 163 ABC music file with the extracted tune(s)
Tune-71234-newpage.ps 6 PostScript
Tune-71234-newpage.txt 163 Plain-text file with the extracted tune(s)
Tune-71235-get.log 5793 Log file, useful mostly for debugging
These files should be available for 24 hours.