InsightSoftwareConsortium / InsightSoftwareConsortium/ITKPythonPackage

COMP: Pinned CastXML 0.6.5 cannot parse gcc-toolset-14 `<limits>` (`_Float32`/`F32`) — blocks all manylinux_2_28 wheel builds

Open
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bug
Dominant language
CMake
Stars
66
Forks
25
Avg merge
1d 18h
Merged PRs (30d)
2

Description

The CastXML 0.6.5 binary used by the manylinux_2_28 wheel builds cannot parse GCC 14's ``, so **every** Linux Python wrapping job fails for remote modules — on `main`, not only on PRs. CastXML 0.7.0 (2026-02-25) postdates the pin and the equivalent gcc-13 defect was fixed upstream, so bumping the pinned CastXML is the likely fix.

Failure detail and error text

manylinux_2_28 dockcross containers now ship `gcc-toolset-14`. GCC 14's `` uses the `__glibcxx_float_n(32)` macro family, which expands to `F32` floating literal suffixes and `__builtin_huge_valf32`. CastXML 0.6.5's embedded Clang does not support these:

```
invalid suffix 'F32' on floating constant
typedef redefinition with different types ('float' vs 'struct __castxml_Float32_s')
```

Reported location: `/opt/rh/gcc-toolset-14/root/usr/include/c++/14/limits:1989`.

Scope of impact

- All 8 Linux Python wrapping jobs fail.
- Reproduced on module `main` branches — this is not introduced by any PR.
- Affects **any** ITK remote module that builds Python wheels on manylinux_2_28, i.e. the whole remote-module wheel fleet.
- First observed during CI triage of ITKMontage PR #242 (merged 2026-04-15).

Upstream status and suggested fixes, in order of preference

- CastXML releases since the 0.6.5 pin: v0.6.9, v0.6.10 (2024-11-27), v0.6.11 (2025-02-11), v0.6.12/v0.6.13 (2025-08-28), **v0.7.0 (2026-02-25)**.
- Upstream CastXML#251 "gcc-13.2.0 unknown type name `_Float32`" — CLOSED 2024-01-23. Same defect class, already fixed for gcc-13.

1. **Bump the pinned CastXML binary** in the wheel-build docker images to v0.7.0 (or ≥0.6.10) and re-run a Linux wrapping job. This is the expected fix and should be tried first.
2. If 0.7.0 still fails on gcc-14, file a fresh upstream issue at https://github.com/CastXML/CastXML with the `limits:1989` reproducer.
3. Stop-gap: pin the dockcross image tags back to a `gcc-toolset-13` revision.
4. Alternative: configure CastXML to use its own bundled Clang headers rather than the GCC toolset headers.

Contributor guide

No contributing guide indexed for this repository

Research direction

Start by locating the pinned CastXML binary in the wheel-build Docker image definitions and checking the current Linux wrapping configuration. Update the pin to a supported release, run a manylinux_2_28 Linux wrapping job, and consider the issue done when the affected Python wheel jobs pass with GCC 14.

Written by the indexing model from the issue text.

Assessment

Tech stack
cmake, docker, python
Domain
build-system, ci-cd, devops
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
58/100

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