Bug 2382683 - Backport fix for miscompilation of rust toolchain with pgo
Summary: Backport fix for miscompilation of rust toolchain with pgo
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Fedora
Classification: Fedora
Component: llvm
Version: rawhide
Hardware: ppc64le
OS: Linux
unspecified
medium
Target Milestone: ---
Assignee: Tom Stellard
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-07-22 20:11 UTC by Paul Murphy
Modified: 2025-08-03 01:15 UTC (History)
14 users (show)

Fixed In Version: llvm-20.1.8-3.fc43 llvm-20.1.8-3.fc42
Clone Of:
Environment:
Last Closed: 2025-07-30 13:49:12 UTC
Type: ---
Embargoed:
npopov: mirror+


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System ID Private Priority Status Summary Last Updated
Red Hat Issue Tracker FC-1840 0 None None None 2025-07-23 08:04:52 UTC

Description Paul Murphy 2025-07-22 20:11:58 UTC
LLVM 20 on rawhide fails to build a function pgo optimized rust compiler on ppc64le. Enabling rust's LLVM IR Verification, LLVM produces an ICE similar to https://github.com/llvm/llvm-project/issues/138208. Likewise, rhbz#2367960 was also opened against this bug.

I have locally backported and verified the fix for llvm#138208 also fixes the quiet failures observed while building the pgo-optimized rust toolchain and building rust-hyper-utils.

Reproducible: Always

Steps to Reproduce:
1. Enable PGO in rust package
1a. Optionally, enable rust.verify-llvm-ir to view the LLVM IR error.  
2. Build on rust
3. Review logs for various test failures like segfaults or borrow errors.

Comment 1 Fedora Update System 2025-07-29 16:22:16 UTC
FEDORA-2025-18488216e7 (llvm-20.1.8-3.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2025-18488216e7

Comment 2 Fedora Update System 2025-07-30 07:31:32 UTC
FEDORA-2025-dd4673b64d (llvm-20.1.8-3.fc42) has been submitted as an update to Fedora 42.
https://bodhi.fedoraproject.org/updates/FEDORA-2025-dd4673b64d

Comment 3 Fedora Update System 2025-07-30 13:49:12 UTC
FEDORA-2025-18488216e7 (llvm-20.1.8-3.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 4 Fedora Update System 2025-07-31 01:31:56 UTC
FEDORA-2025-dd4673b64d has been pushed to the Fedora 42 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2025-dd4673b64d`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2025-dd4673b64d

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 5 Fedora Update System 2025-08-03 01:15:14 UTC
FEDORA-2025-dd4673b64d (llvm-20.1.8-3.fc42) has been pushed to the Fedora 42 stable repository.
If problem still persists, please make note of it in this bug report.


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