[Sol2] make CMake config-version arch-independent

[jrklasen]

Make the AnyPlatform config-version arch-independent (else 32-bit consumers reject the 64-bit-built config).

[jrklasen]

Sol2 was just added erlier today as a dependency for OSRM, the OSRM recipe revield this issue, see #13992.

[imciner2]

Um, what do you mean by

(else 32-bit consumers reject the 64-bit-built config).

If you have different integer sizes on the two API sides, that is actually a problem. Shouldn't the fix be to build Sol2 as 32-bit on the platforms that are 32-bit?

[jrklasen]

Sorry I was traveling and didn't manage to get back to this earlier.

You're right that a real integer-size mismatch would be a problem — but that's not the case here.

Sol2 is header-only hence AnyPlatform(). The only issue is CMake metadata — by default write_basic_package_version_file() bakes the build host's sizeof(void*) into the config, so find_package(sol2) rejects it on a 32-bit consumer (#13992). For headers there's nothing to link, so that guard is spurious.

The fix is the ARCH_INDEPENDENT flag, which is documented for exactly this — same thing nlohmann_json does (#1697). I've updated the recipe to pass it upstream instead of post-editing the generated file, which also drops the brittle hardcoded "8".

Is this fine like this?

[jrklasen]

Hi @imciner2 may I ask you for any thoughts on this?

[jrklasen]

Does anyone have any suggestions on how to proceed with this?