ld: warning: no platform load command found in sys-o.a assuming macOS

[IanButterworth]

I assume this is minor given it correctly assumes macOS

Output ──────  22.320461 seconds
    LINK usr/lib/julia/sys.dylib
ld: warning: no platform load command found in '/Users/ian/Documents/GitHub/julia/usr/lib/julia/sys-o.a[2](text#0.o)', assuming: macOS
ld: warning: no platform load command found in '/Users/ian/Documents/GitHub/julia/usr/lib/julia/sys-o.a[3](text#1.o)', assuming: macOS
ld: warning: no platform load command found in '/Users/ian/Documents/GitHub/julia/usr/lib/julia/sys-o.a[4](text#2.o)', assuming: macOS
ld: warning: no platform load command found in '/Users/ian/Documents/GitHub/julia/usr/lib/julia/sys-o.a[5](metadata.o)', assuming: macOS
ld: warning: no platform load command found in '/Users/ian/Documents/GitHub/julia/usr/lib/julia/sys-o.a[6](sysimg.o)', assuming: macOS
    JULIA stdlib/Unicode.release.image

macOS Sonoma

julia> versioninfo()
Julia Version 1.11.0-DEV.593
Commit f2d1276be8 (2023-10-03 12:04 UTC)
Platform Info:
  OS: macOS (arm64-apple-darwin23.0.0)
  CPU: 10 × Apple M2 Pro
  WORD_SIZE: 64
  LLVM: libLLVM-15.0.7 (ORCJIT, apple-m1)
  Threads: 1 on 6 virtual cores

[gbaraldi]

https://projects.blender.org/blender/blender/pulls/110243/files it seems we need to pass a linker flag

[vtjnash]

Apple is about 2 years behind with publishing their usual documentation for this sort of thing (at https://github.com/apple-oss-distributions/ld64), so we may not learn how to fix this for a while

Someone just observed (17 minutes ago) on a forum elsewhere on the internet that this means our target triple is not correct (missing the OS version)
https://discourse.llvm.org/t/expressing-the-darwin-macos-target-build-command-in-llvm-ir/74198/2?u=vtjnash

Which causes this part of LLVM not to function correctly: https://reviews.llvm.org/D29044

[vtjnash]

This is the part of the code that makes that decision, an in particular, it seems that it must not return early or reach the emitVersionMin as that call emits this warning (must be set >= 10.14). But we intentionally destroy this Target information in the aotcompile pass, since 8678b5e

https://github.com/llvm/llvm-project/blob/main/llvm/lib/MC/MCStreamer.cpp#L1351-L1427
https://github.com/llvm/llvm-project/blob/main/llvm/lib/MC/MCStreamer.cpp#L1306

[gbaraldi]

Can we add the version there?

[vtjnash]

Yeah, we are explicitly using a platform there whose last released version was 10.4. I think we need the string "darwin18" (or later) to fix this.