Does scripts/auxilar/make-regtest-pngs.sh function properly?

[John Wheeler]

I am trying to get the process documented in CG: 9.5 "Pixel-base regtest 
comparison" to run.   But, I am not able to get the command

./make-regtest-pngs.sh -j4 -o

to run without error.  Using git bisect points to commit 
c85e9950a70d1765e4b9a637a737d873975dfb59, "Framework-ps: rewrite system 
clipping to be output format-agnostic" as the point at which it started 
failing.

On the other hand, If I have a successfully generated 
'old-regtest-results',

./make-regtest-pngs.sh -j4 -n

will happily run well past that commit.

I see a lot of discussion on !1272 saying the script should be kept, 
which seems to imply that the script should works.

Is this a known issue?

Thank you,

John Wheeler