Adding support for building powerpc64le (ppc64le) version

[HeavyTony2]

I maintain the Conda-Forge package since mini-racer is now a dependancy of another package I maintain. (https://github.com/conda-forge/mini-racer-feedstock).

So basically, I'd like to build ppc64le. For now, I've not been able to build mini-racer for that, even when modifying some elements in v8_build.py.

I'm well aware this is a tricky request.

I've tried to buy V8 for that arch on Google Colab.

!/content/depot_tools/gn gen /content/v8build --args="target_cpu=\"powerpc64le\""

ERROR at //build/config/rust.gni:372:1: Assertion failed.
assert(!toolchain_has_rust || rust_target_arch != "")
^-----
See //BUILD.gn:12:1: whence it was imported.
import("//build/config/rust.gni")
^-------------------------------

This was the error that I also had when trying to build mini-racer.

Hower, I had something more promising with
!/content/depot_tools/gn gen /content/v8build --args="v8_target_cpu=\"powerpc64le\""

I'd be very grateful if you could work on a way to build Mini-Racer on ppc64le, but once again, I know this isn't an easy one.

[bpcreech]

Hi!

It seems like this might be possible, since there are traces of ppc support in the v8 build and its many dependencies.

It's even possible we might be able to cross-compile it; the v8 project does appear to maintain a Linux sysroot for ppc64le. (Cross-compiling would be ideal because then we can use a typical Intel-based Github Actions runner to build it, as we happen to already do for Linux aarch64 builds.)

I think this would require at minimum small changes to builder/v8_build.py. There are build instructions here: https://bpcreech.com/PyMiniRacer/contributing/. If you can make that working and make a PR, then we can get ppc support into official mini_racer releases.

But I am not sure it's possible with only small changes... it might require, e.g., major patchfiles into the v8 ecosystem, which would make this less likely to be something anyone wants to do or maintain. Hard to know without trying it! (And I for one have not had time try it!)

[HeavyTony2]

Thanks, I'll try to investigate it in the following days.