build: Bump clang minimum supported version to 19 #36036

pull maflcko wants to merge 3 commits into bitcoin:master from maflcko:2608-clang-19 changing 6 files +19 −19

maflcko commented at 1:47 PM on August 20, 2026: member
Most supported operating systems ship with clang-19 (or later), so bump the minimum to that and allow new code to drop workarounds for previous clang bugs.

(For this bump, only C++20 CTAD will become available.)

This patch will only be released in version 33.x, next year (2027).

For reference:
- https://packages.debian.org/bookworm/clang-22
- https://packages.ubuntu.com/noble/clang-20
- CentOS-like 8/9/10 ship clang-21 via Stream
- Free/Open/Net*BSD ship clang-19
- OpenSuse Tumbleweed ships with https://software.opensuse.org/package/clang (clang22); leap:latest with clang-19
- macOS 14: depends/release cross-builds are unaffected and use clang-19
- macOS 14: Native builds use llvm-19-ish via XCode CLT 26.3 since #36287
On operating systems where the minimum Clang version is not shipped by default, the user would have to use GCC, or install Clang in a different way. For example:
- https://packages.debian.org/bookworm/g++ (g++-12)
- https://packages.ubuntu.com/jammy/g++-12
- https://apt.llvm.org/, brew, nix, guix, or compile clang from source, ...
DrahtBot added the label Build system on Aug 20, 2026
DrahtBot commented at 1:47 PM on August 20, 2026: contributor


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External sites
- Code coverage & benchmarks: https://corecheck.dev/bitcoin/bitcoin/pulls/36036
- Ralph review <img src=https://review.fish.foo/assets/bitcoin/bitcoin/36036.png alt="Ralph review status"> https://git.fish.foo/bitcoin/bitcoin/pulls/36036#author-ralph


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Concept ACK hebasto, l0rinc

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Conflicts

Reviewers, this pull request conflicts with the following ones:
- #36042 <sub><img src="https://drahtbot.space/ack_count/bitcoin/bitcoin/36042.svg"></sub> (build: Bump g++ minimum supported version to 13 by maflcko)
- #31507 <sub><img src="https://drahtbot.space/ack_count/bitcoin/bitcoin/31507.svg"></sub> (build: Use clang-cl to build on Windows natively by hebasto)
If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.
maflcko marked this as a draft on Aug 20, 2026
maflcko added this to the milestone 33.0 on Aug 20, 2026
maflcko force-pushed on Aug 20, 2026
DrahtBot added the label CI failed on Aug 20, 2026
maflcko force-pushed on Aug 20, 2026
maflcko removed the label CI failed on Aug 20, 2026
DrahtBot added the label CI failed on Aug 20, 2026
maflcko removed the label CI failed on Aug 20, 2026
DrahtBot added the label CI failed on Aug 20, 2026
maflcko removed the label CI failed on Aug 20, 2026
DrahtBot added the label CI failed on Aug 20, 2026
maflcko commented at 1:57 PM on September 17, 2026: member

This requires an Xcode CLT bump, so please review #36287 first
DrahtBot removed the label CI failed on Sep 17, 2026
DrahtBot added the label Needs rebase on Oct 8, 2026
maflcko force-pushed on Oct 8, 2026
DrahtBot removed the label Needs rebase on Oct 8, 2026
DrahtBot added the label CI failed on Oct 9, 2026
maflcko removed this from the milestone 33.0 on Oct 12, 2026
hebasto commented at 11:25 AM on October 20, 2026: member

Concept ACK.
l0rinc commented at 11:47 AM on October 20, 2026: contributor

Concept ACK, please check if Ralph's objections are valid. Will review properly after it's out of draft - unless you want a detailed review now.
build: Bump clang minimum supported version to 19 e75ace82d9

Type	Reviewers
Concept ACK	hebasto, l0rinc

clang-format: Use Standard: Latest

It should mostly be irrelevant and generally be fine to format any C++
code with the latest standard version. So set that here, but it can be
changed in the future, if there is ever a reason.

5835cbd2e7

ci: warp-ubuntu-2604-x64-8x d70ec1737b
maflcko force-pushed on Oct 20, 2026
maflcko commented at 12:02 PM on October 20, 2026: member

Haven't looked at Ralph's ci nit, but I think it is just a todo that I haven't yet addressed. This requires #36287, so review would be better there first. I've clarified this by dropping the commit from 36287

in .github/workflows/ci.yml:32 in d70ec1737b

  28 | @@ -29,7 +29,7 @@ defaults:
  29 |  jobs:
  30 |    test-each-commit:
  31 |      name: 'test ancestor commits'
  32 | -    runs-on: ${{ github.repository == 'bitcoin/bitcoin' && 'warp-ubuntu-latest-x64-8x' || 'ubuntu-latest' }}
  33 | +    runs-on: ${{ github.repository == 'bitcoin/bitcoin' && 'warp-ubuntu-2604-x64-8x' || 'ubuntu-latest' }}

maflcko commented at 12:07 PM on October 20, 2026:

re Ralph: Was hoping they change the image in September, like last time (https://github.blog/changelog/2024-09-25-actions-new-images-and-ubuntu-latest-changes/), but I guess not anymore

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#36287 build: Bump Xcode CLT minimum supported version to 26.3

build: Bump clang minimum supported version to 19 #36036

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