On Thu, Jul 17, 2025 at 3:23 PM brian m. carlson
<sandals@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On 2025-07-17 at 20:32:24, Ezekiel Newren via GitGitGadget wrote:
> > diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
> > index 7dbf9f7f123c..8aac18a6ba45 100644
> > --- a/.github/workflows/main.yml
> > +++ b/.github/workflows/main.yml
> > @@ -4,6 +4,7 @@ on: [push, pull_request]
> >
> > env:
> > DEVELOPER: 1
> > + RUST_VERSION: 1.87.0
>
> Our discussed plan is to support the version in Debian stable, plus a
> year. So we'd be supporting 1.63.0 for a year after trixie's release.
>
> The reason for that is that people build backports and security updates
> for Git for stable releases of distros and they will use the distro
> toolchain for doing so. Forcing distros to constantly build with the
> latest toolchain is pretty hostile, especially since the lifespan of
> Rust release is six weeks.
>
> If the Rust project provides LTS releases in the future, then we can
> consider adopting those.
The RUST_VERSION variable in .github/workflows/main.yaml had to have a
specific version. 1.87.0 was selected since that's what I was using
locally. Elijah made me aware that an older version of rust might be
desired, but didn't know which one. I'll switch to 1.63.0 or whatever
the community decides.
> > +if [ "$rust_target" = "release" ]; then
> > + rust_args="--release"
> > + export RUSTFLAGS='-Aunused_imports -Adead_code'
> > +elif [ "$rust_target" = "debug" ]; then
> > + rust_args=""
> > + export RUSTFLAGS='-Aunused_imports -Adead_code -C debuginfo=2 -C opt-level=1 -C force-frame-pointers=yes'
>
> Can you say a little about why these options are needed and the defaults
> are inadequate? For instance, I build with the default options both in
> my personal projects and at work and don't see a problem.
What I found is that if I have a Rust function
#[no_mangle]
pub fn call_from_c(arg: u64) {}
which is only meant to be called from C and isn’t called from
elsewhere in Rust, then cargo will misidentify this function as dead
code. This was the reason for adding ‘-Adead_code’.
The reason for adding ‘-Aunused_imports’ is somewhat IDE related; if I
paste code somewhere, RustRover will sometimes automatically add the
necessary imports. However, if I delete a chunk of code, it’ll
highlight the imports that are no longer used if I scroll to the top
of the file, but it won’t automatically remove them. Since they
aren’t automatically removed, it’s easier to build with
‘-Aunused_imports’.
The remaining arguments, ‘-C debuginfo=2 -C opt-level=1 -C
force-frame-pointers=yes’ is to make /usr/bin/perf output more
amenable to analysis.
> I don't know if you plan to do this in a future series, but we'd also
> want cargo's tests to be run as part of CI and we'd want a lint job that
> ran clippy with both 1.63.0 and the latest stable version of Rust to
> make sure things were tidy.
Yeah I'd like that too; we can add that in a future patch series.
> --
> brian m. carlson (they/them)
> Toronto, Ontario, CA
