Got HTTP status 404 Not Found for "http://roaringjelly.org/~jc/music/book/air/JohnWalsh.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-92777-JohnWalsh.ps) >>/Users/jc/w/tmp/Tune-92777-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/air/JohnWalsh.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-92777-193_MissStevensonsStrathspey.abc 778 ABC music file with the extracted tune(s)
Tune-92777-193_MissStevensonsStrathspey.pdf 21722 Portable Data Format
Tune-92777-193_MissStevensonsStrathspey.ps 37672 PostScript
Tune-92777-193_MissStevensonsStrathspey.txt 778 Plain-text file with the extracted tune(s)
Tune-92777-HaandMeDoonDaFiddle.abc 156 ABC music file with the extracted tune(s)
Tune-92777-HaandMeDoonDaFiddle.ps 6 PostScript
Tune-92777-HaandMeDoonDaFiddle.txt 156 Plain-text file with the extracted tune(s)
Tune-92777-JohnWalsh.abc 145 ABC music file with the extracted tune(s)
Tune-92777-JohnWalsh.ps 6 PostScript
Tune-92777-JohnWalsh.txt 145 Plain-text file with the extracted tune(s)
Tune-92777-get.log 14203 Log file, useful mostly for debugging
These files should be available for 24 hours.