rust 1.81.0 buildable with LLVM 17.x?

[he32]

This is perhaps more of a question or a "release management" issue, perhaps even "documenting the latter".

In my quest to continue to have rust buildable & installable in NetBSD's pkgsrc system, I've now come to rust 1.81.0.

The package has an option to either build with an external LLVM (and libunwind) or with the embedded version of at least LLVM
in the rust tarball.

When going from rust 1.80.1 to rust 1.81.0 I find that the rust compiler no longer builds with an external LLVM 17.x.

The last time a bump in the requirement for an external LLVM happened was in the 1.79.0 release.

My question is whether someone missed bumping the requirement in the rust release notes for 1.81.0, or whether
the errors I'm seeing while trying to use an external LLVM are of my own or "our own" doing. The errors start with

[ 29%] Building CXX object COFF/CMakeFiles/lldCOFF.dir/CallGraphSort.cpp.o
[ 30%] Building CXX object MachO/CMakeFiles/lldMachO.dir/Arch/ARM64Common.cpp.o
In file included from /usr/pkgsrc/wip/rust181/work/rustc-1.81.0-src/src/llvm-project/lld/wasm/Driver.cpp:141:
/usr/pkgsrc/wip/rust181/work/rustc-1.81.0-src/build/x86_64-unknown-netbsd/lld/build/wasm/Options.inc:44:122: error: macro "OPTION" requires 13 arguments, but only 12 given
   44 | OPTION(prefix_0, llvm::StringLiteral("<input>"), INPUT, Input, INVALID, INVALID, nullptr, 0, 0, nullptr, nullptr, nullptr)
      |                                                                                                                          ^
/usr/pkgsrc/wip/rust181/work/rustc-1.81.0-src/src/llvm-project/lld/wasm/Driver.cpp:134: note: macro "OPTION" defined here
  134 | #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS,         \
      | 

For some reason the build appears to want to build LLD.

Did someone not test building with an external LLVM 17.x? Does rust now from 1.81.0 in fact need an external LLVM >= 18?

[DianQK]

#130487 drop LLVM 17 at Rust 1.83.0. It looks like your logs are building the LLVM bundled with Rust?

[he32]

#130487 drop LLVM 17 at Rust 1.83.0. It looks like your logs are building the LLVM bundled with Rust?

Actually no, as I said, it's trying to build LLD (I don't know why). The percentage progress starts with

-- Build files have been written to: /usr/pkgsrc/wip/rust181/work/rustc-1.81.0-src/build/x86_64-unknown-netbsd/lld/build
running: cd "/usr/pkgsrc/wip/rust181/work/rustc-1.81.0-src/build/x86_64-unknown-netbsd/lld/build" && DESTDIR="" "cmake" "--build" "." "--target" "install" "--config" "Release" "--" "-j" "20"
[  0%] Built target intrinsics_gen
[  3%] Building Options.inc...
[  3%] Building Options.inc...

[he32]

And ... the build phases it has started are:

: {110} egrep '^Build' list.01
Building bootstrap
Building stage0 library artifacts (x86_64-unknown-netbsd)
Building compiler artifacts (stage0 -> stage1, x86_64-unknown-netbsd)
Building LLD for x86_64-unknown-netbsd
: {111} 

[DianQK]

Ah, I guess it's #124129. You can disable lld.

[DianQK]

IIUC, after #126282, you just need to set the channel to stable.
cc @lqd

[he32]

Ah, I guess it's #124129. You can disable lld.

That would explain it, I'm pursuing that hint.

[lqd]

Yes, just set rust.lld=false if you don’t want to build lld. If you’re using an external llvm, not building dev/nightly, not building for x64 linux and so on, it should already be disabled though. In case not, setting it explicitly will disable it for sure.

edit: ah you’re probably using the dist profile, lld is enabled there.

[he32]

[...] Yes, just set rust.lld=false if you don't want to build lld.

Thanks for the hint, I can confirm that I now have 1.81.0 building with an external LLVM 18.x on NetBSD/amd64 (w86_64).

[...] If you're using an external llvm

Yep.

[...] not building dev/nightly,

Nope, building from a complete release tarball.

[...] not building for x64 linux

Yep, this is native building on NetBSD/amd64 10.0.

[...] and so on, it should already be disabled though.

It doesn't look like it...

[...]In case not, setting it explicitly will disable it for sure.

Yep, that I can confirm.

[lqd]

#126701 enabled lld on the dist profile

[he32]

OK, that worked around the issue for the package.
Again, many thanks for the quick hints which led me on the correct path.