Re: [gentoo-dev] Re: Rust flags

[Andrew Savchenko]

On Tue, 14 May 2019 16:58:16 -0700 Georgy Yakovlev wrote:
> On Tuesday, May 14, 2019 3:01:48 PM PDT Andrew Savchenko wrote:
> > On Tue, 14 May 2019 11:47:04 -0700 Georgy Yakovlev wrote:
[...]
> > > I have this in make.conf for quite some time.
> > >
> > > RUSTFLAGS="-Ctarget-cpu=native -v"
> > >
> > > it just works(tm) as you expect it to.
> >
> > Well, it does not, at least for me. Right now I'm building
> > torbrowser from mozilla overlay and content of RUSTFLAGS from
> > make.conf doesn't show up in rustc arguments.
> >
> That's something about mozbuild, not the variable itself.
> check about:buildconfig page of torbrowser.
>
> RUSTFLAGS show up for me on that page, not 100% sure if they actually get
> applied.

Yes, they are showing up, though I don't see them applied in the
build log.

> I have no idea how it calls rustc. if it's cargo then to see verbose
> invocations you need to find where the build system calls it and add "-vv"
>
> btw, be careful with -C opt-level=3 for ff or derivatives, it was known to
> cause segfaults some time ago.
>
> for regular packages this variable works fine.
>
> > Moreover there is no mention of RUSTFLAGS in either man rustc or
> > rust/cargo eclasses.
>
> because it's a variable used by cargo to call rustc with given params, not by
> rustc itself.
>
> This has nothing to do with eclass, it's cargo setting supposed to be set by
> user.
>
> CARGO-RUSTC(1) page does mention it
>
> more details here:
> https://github.com/rust-lang/cargo/blob/master/src/doc/src/reference/
> environment-variables.md

Thanks, it indeed has it. I used to read man pages and man
cargo-rustc don't mention it, though github docs does.

Best regards,
Andrew Savchenko