You're going about this a very long way around, why don't you just cross compile FPC for Aarch64 Linux from a working installation on i386 or x86_64 Linux?
I tried that first, keep getting a x86 version, I suspect the build instructions are wrong.
Seems to be holes in the build process.
fpcupdeluxe seems to expect stuff the Gentoo64 does not come with as standard.
Getlazarus setup.sh is also a bit dated.
In the last week or so I must have made about 20 FPC builds
I was hoping a Aarch64 Laz/FPC build would then allow an Aarch64 Ultibo build.
That way I can compare Linux Aarch64 against Ultibo Aarch64 builds.
Hoping Aarch64 FPC will help towards getting Aarch64 Ultibo going.
A lot of ML/CV stuff is in C code, so translate that to fpc and test on Pi in Linux before doing it in Ultibo.
ArmV8 / Aarch64 / ARM64... what would it take?
Probably more guess work, more learning or someone who knows what they are doing
FPC Aarch64 support is new too, perhaps later than fpc 3.0.0.
But as you know fpc requires a 3.0.0.binary to build later versions.
You are probably right, I will have to cross compile version 3.0.0 on a x86 box to aarch64.
Lots for me to learn, I did hope fpcupdeluxe would work out of the box.
I suspect it may if all the prerequisite are met.
Lots of source code is showing up when fpcupdeluxe runs, but not an Aarch64 compiler.
Getlazarus setup.sh looks to be the most agnostic script.
If I compare the x86 Linux one to the Raspberry version, I might get more clues.