it looks like the LuaTeX binaries were compiled with "-g -O2", but
running "readelf" and "objdump" shows that they're stripped, so I
don't think that that's the issue here.
FWIW, it's my understanding that what matters for execution speed is not
the presence or absence of debug symbols (-g), but whether optimization
was enabled (-O2 or similar).
Debian Sid arm64 LuaTeX: 0m15.392s
Debian Sid arm64 pdfTeX: 0m7.914s
TeX Live 2023 arm64 LuaTeX: 0m0.737s
TeX Live 2023 x86_64 pdfTeX: 0m0.156s
TeX Live 2023 x86_64 LuaTeX: 0m0.156s
Not sure whether to conclude it's arm-specific or sid-specific or both
from those numbers, but I suppose a few more runs would show.
LuaTeX 2024 could be getting slowed down a bit by the additional access
checking, I suppose, but there were no significant changes in pdfteX in
2024, so that can't be the whole explanation.
FWIW, building lualatex.fmt on my x86_64-linux (Rocky Linux 9.3) home
machine, with the TL luahbtex binary, took about six seconds.
Rebuilding all the formats took about 80 seconds, last time it happened.
Best,
Karl
