rust: source build fails when running under rosetta 2

[lukaso (Lukas Oberhuber)]

When I look to build an x86_64 version of rust under rosetta arch -x86-64 /bin/zsh, it fails with:

:info:build DYLD_LIBRARY_PATH="/Users/lukasoberhuber/macports-gimp3-x86_64/var/macports/build/_Users_lukasoberhuber_macports-gimp3-x86_64_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_rust/rust/work/rustc-1.71.1-src/build/x86_64-apple-darwin/stage1/lib" "/Users/lukasoberhuber/macports-gimp3-x86_64/var/macports/build/_Users_lukasoberhuber_macports-gimp3-x86_64_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_rust/rust/work/rustc-1.71.1-src/build/x86_64-apple-darwin/stage1/bin/rustc" "-vV" "-Wrust_2018_idioms" "-Wunused_lifetimes" "-Wsemicolon_in_expressions_from_macros" "-Dwarnings" "-Clinker=/Users/lukasoberhuber/macports-gimp3-x86_64/var/macports/build/_Users_lukasoberhuber_macports-gimp3-x86_64_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_rust/rust/work/compwrap/ld/usr/bin/clang" "-Zunstable-options" "--check-cfg=values(bootstrap)" "--remap-path-prefix" "/Users/lukasoberhuber/macports-gimp3-x86_64/var/macports/build/_Users_lukasoberhuber_macports-gimp3-x86_64_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_rust/rust/work=/Users/lukasoberhuber/macports-gimp3-x86_64/libexec/rust/src" "-Z" "force-unstable-if-unmarked"
:info:build -------------
:info:build --- stderr
:info:build <jemalloc>: Error allocating TSD
:info:build rustc exited with signal: 6 (SIGABRT)

Why would I want to do this relatively exotic build? Because Circle CI is getting ready to get rid of all Intel build bots and so this is how I will have to build the intel version.

This would not be an issue if macports could use pre-built binaries for rust when building in a custom location and without sudo, but I don't think that's how it work.

[lukaso (Lukas Oberhuber)]

Built on M1 Mac but with terminal in rosetta mode

[lukaso (Lukas Oberhuber)]

I've now created a upstream issue: ​https://github.com/rust-lang/rust/issues/116512 and an downstream issue: ​https://gitlab.gnome.org/Infrastructure/gimp-macos-build/-/issues/55

[lukaso (Lukas Oberhuber)]

If we want to work around this, this command will detect (return 1) if running under rosetta 2: sysctl -n sysctl.proc_translated.

I'm not sure how to do an if based on running a command in a Portfile or I'd give it a go.

[lukaso (Lukas Oberhuber)]

I have tried with adding that check to my Portfile. Rust now builds successfully.

Here's the specific bit:

if { ${os.platform} eq "darwin" && ${os.major} > 14 } {
    # check if running in rosetta2 and don't set jemalloc if so
    try {
        set in_rosetta2 [exec sysctl -n sysctl.proc_translated]
        if { ${in_rosetta2} == 0 } {
            configure.args-append   --set=rust.jemalloc
            ui_debug "proc_translated = 0. Enabling jemalloc."
        } else {
            ui_debug "proc_translated = 1. Disabling jemalloc."
            depends_build-append        port:libatomic_ops
        }
    } catch {
        ui_debug "proc_translated errored. Disabling jemalloc."
        depends_build-append        port:libatomic_ops
        # Handle non-zero return of proc_translated gracefully, optionally log the error.
    }
    if { ${os.arch} eq "arm" } {
        configure.args-append   --set=rust.jemalloc
        # specify the number of significant virtual address bits in jmalloc
        # the configure script calls cpuid, but it does not work properly on Rosetta 2
        # see https://github.com/jemalloc/jemalloc/issues/1997#issuecomment-1041589117
        build.env.x86_64-append     JEMALLOC_SYS_WITH_LG_VADDR=48
        destroot.env.x86_64-append  JEMALLOC_SYS_WITH_LG_VADDR=48
    }
}

I have run into a different error later in the build, but this is a start.

[lukaso (Lukas Oberhuber)]

OK, actually, the different error appears to be related to XCode 15 rather than anything related to rosetta2. So once that is fixed, building under rosetta2 should work.

[lukaso (Lukas Oberhuber)]

PR to patch rust: ​https://github.com/macports/macports-ports/pull/21015