Regenerating *.opt.urls doesn't do anything

[Thomas Koenig via Gcc]

Hi,

I am currently working on a patch which adds an option, and
failing in regenerating the gcc/fortran/lang.opt.urls file.
I tried

make -C gcc html fortran.html d.html
make -C gcc regenerate-opt-urls

as advised in

https://gcc.gnu.org/pipermail/fortran/2024-September/061030.html

but that fails for me. I see a repeated warning

makeinfo: warning: set_from_cmdline: unknown variable 
CONTENTS_OUTPUT_LOCATION

and nothing is generated anywhere where I can find it, and especially
not in the source tree.

This is on cfarm120, which has texi2any (GNU texinfo) 6.7 .

Anything I should be doing different?

Best regards

        Thomas