Update libmultiprocess subtree to fix build issues

ryanofsky commented at 9:59 pm on August 22, 2025: contributor

Includes:

These changes are needed to build fix libmultiprocess build issue that happens on OpenBSD and work around an incompatibility between GCC versions <14 and cap’nproto versions <0.9 when compiling with c++20 that was fixed upstream in https://github.com/capnproto/capnproto/pull/1170. The issues were reported:

The fixes added CI jobs upstream to catch these issues earlier.

The changes can be verified by running test/lint/git-subtree-check.sh src/ipc/libmultiprocess as described in developer notes and lint instructions

Squashed 'src/ipc/libmultiprocess/' changes from b4120d34bad2..1b8d4a6f1e54

1b8d4a6f1e54 Merge bitcoin-core/libmultiprocess#194: mpgen: Work around c++20 / capnproto 0.8 incompatibility
f1fad396bf5f Merge bitcoin-core/libmultiprocess#195: ci: Add openbsd
eed42f210d17 ci: Bump all tasks to actions/checkout@v5
486a510bbeff ci: Remove ancient and problematic -lstdc++fs in mpexample
dd40897efe79 Add missing thread include
98414e7d2867 ci: Add openbsd
dc3ba2204606 cmake, doc: Add check for CVE-2022-46149
cb170d4913a2 Merge bitcoin-core/libmultiprocess#193: build: require CapnProto 0.7.0 or better
8ceeaa6ae401 ci: Add olddeps job to test old dependencies versions
c4cb758eccb5 mpgen: Work around c++20 / capnproto 0.8 incompatibility
30930dff7b06 build: require CapnProto 0.7.0 or better

git-subtree-dir: src/ipc/libmultiprocess
git-subtree-split: 1b8d4a6f1e54b92708bd2ad627ec6d440a1daf3d

dd68d0f40b

Merge commit 'dd68d0f40b614474f24469fbe1ba02f8f9146b31' into pr/subtree-3 323b3fd272

DrahtBot renamed this:
~~Update libmultiprocess subtree to fix build issues~~
Update libmultiprocess subtree to fix build issues
on Aug 22, 2025

DrahtBot commented at 9:59 pm on August 22, 2025: contributor

The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

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For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/33241.

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ACK	hebasto, Sjors, achow101

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DrahtBot added the label CI failed on Aug 22, 2025

DrahtBot commented at 10:56 pm on August 22, 2025: contributor

🚧 At least one of the CI tasks failed. Task ARM, unit tests, no functional tests: https://github.com/bitcoin/bitcoin/runs/48709103843 LLM reason (✨ experimental): The CI failure is caused by a test timeout during the execution of the ‘mptest’ test.

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.

DrahtBot removed the label CI failed on Aug 22, 2025

maflcko commented at 6:10 am on August 23, 2025: member

Task ARM, unit tests, no functional tests: https://github.com/bitcoin/bitcoin/runs/48709103843 LLM reason (✨ experimental): The CI failure is caused by a test timeout during the execution of the ‘mptest’ test.

Unrelated, but this failure looks real? The unit test should normally pass in a few milliseconds, so taking 40 minutes seems odd?

https://cirrus-ci.com/task/5714850606743552?logs=ci#L2822: [23:07:33.279] 3/148 Test [#3](/bitcoin-bitcoin/3/): mptest ............................... Passed 0.03 sec https://cirrus-ci.com/task/4911861373599744?logs=ci#L3101: [22:41:29.095] 148/148 Test [#3](/bitcoin-bitcoin/3/): mptest ...............................***Timeout 2400.10 sec

TheCharlatan commented at 9:19 am on August 23, 2025: contributor

failure looks real? The unit test should normally pass in a few milliseconds, so taking 40 minutes seems odd?

I reproduced this by repeatedly calling mptest. Took about 50'000 tries until it hung indefinitely.

hebasto commented at 1:22 pm on August 23, 2025: member

I’ve tested this branch on OpenBSD. It works fine.

However, building on NetBSD remains broken: https://github.com/bitcoin-core/libmultiprocess/pull/196.

ryanofsky commented at 1:41 pm on August 23, 2025: contributor

re: #33241 (comment)

failure looks real? The unit test should normally pass in a few milliseconds, so taking 40 minutes seems odd?

re: #33241 (comment)

I reproduced this by repeatedly calling mptest. Took about 50'000 tries until it hung indefinitely.

Yes the failure is real, and this is probably issue https://github.com/bitcoin-core/libmultiprocess/issues/189, which I also reproduced by running the unclean disconnect test thousands of times, and thought was more rare. I have a pretty clear idea of how I want to fix this now so will work on it.

hebasto commented at 5:39 pm on August 23, 2025: member

failure looks real? The unit test should normally pass in a few milliseconds, so taking 40 minutes seems odd?

I reproduced this by repeatedly calling mptest. Took about 50'000 tries until it hung indefinitely.

Is this a newly introduced issue, or does it also exist on the master branch?

ryanofsky commented at 6:12 pm on August 23, 2025: contributor

Is this a newly introduced issue, or does it also exist on the master branch?

I’m not sure if it’s been seen in master but I would expect it happens in master. Seems unlikely any change in this PR would cause it, see #33244

hebasto approved

hebasto commented at 7:30 am on August 24, 2025: member

ACK 323b3fd27283282f2f8eb1096f56f23d8230f2d6, I’ve reproduced the subtree update locally. The two issues noted in this PR are unrelated to its changes and can be addressed separately.

Sjors commented at 8:45 am on August 25, 2025: member

ACK 323b3fd27283282f2f8eb1096f56f23d8230f2d6

maflcko added this to the milestone 30.0 on Aug 25, 2025

achow101 commented at 8:37 pm on August 25, 2025: member

ACK 323b3fd27283282f2f8eb1096f56f23d8230f2d6

Verified the subtree update and that it fixes the Ubuntu issue (after removing the 0.8.0 restriction).

achow101 merged this on Aug 25, 2025

achow101 closed this on Aug 25, 2025

Update libmultiprocess subtree to fix build issues #33241

Code Coverage & Benchmarks

Reviews