Your message dated Fri, 11 Apr 2025 17:24:18 +0000
with message-id <e1u3i70-0058tc...@fasolo.debian.org>
and subject line Bug#1095862: fixed in rustc 1.85.0+dfsg2-3
has caused the Debian Bug report #1095862,
regarding rustc unsoundness/miscompilations on i386
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
misconfiguration somewhere. Please contact ow...@bugs.debian.org
immediately.)


-- 
1095862: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1095862
Debian Bug Tracking System
Contact ow...@bugs.debian.org with problems
--- Begin Message ---
Source: rustc
Version: 1.84.0+dfsg1-1
Severity: serious
Tags: upstream
Justification: Policy 2.2.1
X-Debbugs-Cc: debian-r...@lists.debian.org, sylves...@debian.org

Filing this bug to have a record in BTS - I'll file a separate one for
release.debian.org about the broader baseline question.

This issue came up back in November on debian-devel/-release:

https://lists.debian.org/debian-release/2024/11/msg00443.html

My original mail, partially wrongly summarizing the issue.

https://lists.debian.org/debian-release/2024/11/msg00445.html

My reponse linking to more upstream details, including why downgrading to i586
in LLVM/rustc doesn't work.

It boils down to the following:

- Debian's i386 baseline is currently 32-bit x86 without MMX or SSE (i686)
- Debian's LLVM and rustc packages accordingly patch their i686 targets to
  remove SSE support, which would be part of that target's baseline upstream
  otherwise [0,1]
- Upstream LLVM and rustc consider this combination unsound and unfixable (for
  IMHO valid reasons) because it can cause subtle miscompilations leading to
  runtime crashes, in addition to the (usual, expected) different semantics of
  x87 and SSE2 floating point implementations [2,3]

I see the following options:

A) bump i386 baseline for Trixie to match LLVM/rustc's upstream i686 target,
   i.e. Pentium 4 *with* MMX and SSE2 (separate RT bug will be filed shortly)

B) RC-ignore this bug and implications for Trixie, bump baseline for Trixie+1

C) remove LLVM and rustc and all their transitive rdeps (this includes Firefox
   and Chromium, most major Desktop environments, sequoia, and probably a bit
   more) on i386 from Trixie, further reducing the usefulness of this arch

Personally (with my rustc maintainer hat on) I have a strong preference for A).

Please keep responses on details of A) to the corresponding release.debian.org
bug!

Fabian

0: 
https://salsa.debian.org/rust-team/rust/-/blob/debian/sid/debian/patches/behaviour/d-rustc-i686-baseline.patch?ref_type=heads
1: 
https://salsa.debian.org/pkg-llvm-team/llvm-toolchain/-/blob/19/debian/patches/clang-baseline-fix-i386.patch
2: https://github.com/rust-lang/compiler-team/issues/808
3: https://github.com/rust-lang/rust/issues/114479#issuecomment-2072052116

--- End Message ---
--- Begin Message ---
Source: rustc
Source-Version: 1.85.0+dfsg2-3
Done: Fabian Grünbichler <debian@fabian.gruenbichler.email>

We believe that the bug you reported is fixed in the latest version of
rustc, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1095...@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Fabian Grünbichler <debian@fabian.gruenbichler.email> (supplier of updated 
rustc package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmas...@ftp-master.debian.org)


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

Format: 1.8
Date: Fri, 11 Apr 2025 13:40:09 +0200
Source: rustc
Architecture: source
Version: 1.85.0+dfsg2-3
Distribution: unstable
Urgency: medium
Maintainer: Debian Rust Maintainers 
<pkg-rust-maintain...@alioth-lists.debian.net>
Changed-By: Fabian Grünbichler <debian@fabian.gruenbichler.email>
Closes: 1095862
Changes:
 rustc (1.85.0+dfsg2-3) unstable; urgency=medium
 .
   * baseline: enable SSE2 for i386 build (Closes: #1095862)
Checksums-Sha1:
 5c7c2b94834b6d695314bce725740ed158038731 4366 rustc_1.85.0+dfsg2-3.dsc
 095cf1715609671a5945e8c1745b10825af75cc4 139652 
rustc_1.85.0+dfsg2-3.debian.tar.xz
 a9678eb31e7f7a0e060fc094967e2eda257541ef 9681 
rustc_1.85.0+dfsg2-3_source.buildinfo
Checksums-Sha256:
 478bdb6c13c9ae35d22ebc9ff19da646a98e2628102e95bef84c89a4eff0b0c7 4366 
rustc_1.85.0+dfsg2-3.dsc
 5887f0f3262a7ed9e45611c1cf1b2ec4e9ef2aaf940b2359876e28e0993e0511 139652 
rustc_1.85.0+dfsg2-3.debian.tar.xz
 5b6c3240c5873f78213f763350843ea658efa354c482aa0fdb8fe2295b2b65d7 9681 
rustc_1.85.0+dfsg2-3_source.buildinfo
Files:
 c1a2932bab471832e1623ff6767339ee 4366 devel optional rustc_1.85.0+dfsg2-3.dsc
 fc8b2d4be9bb7ff69263f3c3df081b46 139652 devel optional 
rustc_1.85.0+dfsg2-3.debian.tar.xz
 a250cc49635b9104f887826a14b4b1b5 9681 devel optional 
rustc_1.85.0+dfsg2-3_source.buildinfo

-----BEGIN PGP SIGNATURE-----
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=yMAJ
-----END PGP SIGNATURE-----

Attachment: pgpLethSnV72M.pgp
Description: PGP signature


--- End Message ---

Reply via email to