test: Nudge toward QT_STYLE_OVERRIDE=fusion on macOS #951

pull maflcko wants to merge 2 commits into bitcoin-core:master from maflcko:2607-qt-test-macos-style-nullptr-crash-fusion changing 1 files +11 −5

maflcko commented at 12:01 PM on July 22, 2026: contributor
Fixes https://github.com/bitcoin/bitcoin/issues/35771

Using the Fusion style works around QTBUG-49686.

Otherwise, there could be an invalid call under the QMacStyle.

Can be tested via:
```
QT_STYLE_OVERRIDE=macOS  build/bin/test_bitcoin-qt  # fails
QT_STYLE_OVERRIDE=fusion build/bin/test_bitcoin-qt  # passes
```
refactor: Run clang-format on qt test_main.cpp faa50c08b1

test: Nudge toward QT_STYLE_OVERRIDE=fusion on macOS

Using the Fusion style works around QTBUG-49686.

Otherwise, there could be a nullptr-deref under the QMacStyle.

fa0c8337a8

DrahtBot renamed this:
~~test: Nudge toward QT_STYLE_OVERRIDE=fusion on macOS~~
test: Nudge toward QT_STYLE_OVERRIDE=fusion on macOS
on Jul 22, 2026
DrahtBot commented at 12:02 PM on July 22, 2026: contributor



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ACK hebasto

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hebasto commented at 12:11 PM on July 22, 2026: member

Concept ACK. My current WIP branch also uses style overriding.
hebasto commented at 12:24 PM on July 22, 2026: member

So far, this bug has only been reproduced when Qt plugins are linked statically. Unfortunately, this configuration is not covered by CI.
in src/qt/test/test_main.cpp:72 in fa0c8337a8
```
  72 | +#endif
  73 |  
  74 | +#ifdef Q_OS_MACOS
  75 | +    // QMacStyle assumes a Cocoa platform window, which the minimal platform
  76 | +    // does not provide. In particular, painting a QGroupBox can make Qt call
  77 | +    // addSubview: on an invalid native object (QTBUG-49686).
```
hebasto commented at 12:28 PM on July 22, 2026:

Are you sure that QTBUG-49686 is a good reference? Asking because it doesn't mention styles at all.

maflcko commented at 12:40 PM on July 22, 2026:

Yeah, the issue is specific in the title, but the general issue is that a bunch of the code assumes Cocoa, and then throws/aborts/crashes when that assumption is violated with the Minimal platform plugin.

<!-- ci: ``` https://github.com/bitcoin/bitcoin/pull/33509/changes/d40e61e87cfb18f75742c2efa6e705f38e3b36c9
hebasto approved
hebasto commented at 12:50 PM on July 22, 2026: member

ACK fa0c8337a8d42564880715a07b00925d3e95dab1, tested on macOS Tahoe 26.5.2 (Intel).
hebasto commented at 12:52 PM on July 22, 2026: member

@fanquake

Mind checking whether this PR resolves https://github.com/bitcoin/bitcoin/issues/35771 for you?

Type	Reviewers
ACK	hebasto

maflcko commented at 1:05 PM on July 22, 2026: contributor

CI failure looks unrelated:

199/354 Test [#202](/bitcoin-core-gui/202/): test_kernel .......................................................***Failed    0.12 sec
Test setup error: system_error produced by: exp: Out of memory

hebasto commented at 1:06 PM on July 22, 2026: member

So far, this bug has only been reproduced when Qt plugins are linked statically. Unfortunately, this configuration is not covered by CI.

Apparently, @willcl-ark is working in that: https://github.com/bitcoin/bitcoin/pull/35774.
fanquake commented at 1:17 PM on July 22, 2026: member

Mind checking whether this PR resolves https://github.com/bitcoin/bitcoin/issues/35771 for you?

The tests pass with this change.
DrahtBot added the label CI failed on Jul 22, 2026
DrahtBot commented at 2:14 PM on July 22, 2026: contributor


🚧 At least one of the CI tasks failed. <sub>Task Alpine (musl): https://github.com/bitcoin-core/gui/actions/runs/29917983667/job/88916243995</sub> <sub>LLM reason (✨ experimental): CI failed because the test_kernel CTest job crashed during setup due to an out-of-memory error.</sub>

<details><summary>Hints</summary>

Try to run the tests locally, according to the documentation. However, a CI failure may still happen due to a number of reasons, for example:
- Possibly due to a silent merge conflict (the changes in this pull request being incompatible with the current code in the target branch). If so, make sure to rebase on the latest commit of the target branch.
- A sanitizer issue, which can only be found by compiling with the sanitizer and running the affected test.
- An intermittent issue.
Leave a comment here, if you need help tracking down a confusing failure.

</details>
hebasto merged this on Jul 22, 2026
hebasto closed this on Jul 22, 2026
maflcko deleted the branch on Jul 22, 2026

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test: Nudge toward QT_STYLE_OVERRIDE=fusion on macOS #951

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