fix: build failure with bazel 8

[not-matthias]

Root cause: The Github release doesn't contain the instrument-hooks submodule, which leads to errors when including a non-existent file. The same can happen for CMake.

What changed:

• Replaced the git submodule with FetchContent (CMake)
• Test multiple bazel versions

EDIT: The bazel issue can be fixed using git_repository instead of http_archive.

[codspeed-hq]

CodSpeed Performance Report

Merging #24 will degrade performances by 39.19%

_{Comparing cod-1510-bazel-build-is-broken-on-v130 (f615ab6) with main (480ebd8)}

Summary

❌ 4 regressions
✅ 148 untouched

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Mode	Benchmark	BASE	HEAD	Change
❌	Instrumentation	BM_sleep_100ms	435.6 µs	706.1 µs	-38.32%
❌	Instrumentation	BM_sleep_10ms	43.8 µs	70.2 µs	-37.55%
❌	Instrumentation	BM_sleep_1ms	4.1 µs	6.3 µs	-34.99%
❌	Instrumentation	BM_sleep_50ms	216.1 µs	355.3 µs	-39.19%

[Copilot]

Pull Request Overview

This PR fixes a build failure with Bazel 8 by replacing the instrument-hooks git submodule with proper dependency fetching mechanisms. The root cause was that GitHub releases don't include submodule content, leading to build failures when trying to include non-existent files.

Key Changes:

• Replaced git submodule with FetchContent for CMake and a Bazel module extension
• Removed recursive submodule cloning from CI workflows to catch this issue in the future
• Added testing across multiple Bazel versions (7.6.2, 8.4.2, and 9.0.0 pre-release)

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
core/instrument-hooks	Removed the git submodule reference
core/CMakeLists.txt	Added FetchContent to dynamically fetch instrument-hooks dependency
core/BUILD	Removed local instrument_hooks library definition, now references external dependency
MODULE.bazel	Replaced git_override with module extension for instrument_hooks
third_party/extensions.bzl	Created Bazel extension to fetch instrument-hooks via git_repository
third_party/instrument_hooks.BUILD	Added BUILD file for instrument-hooks external dependency
third_party/BUILD	Created package to export third-party configuration files
.github/workflows/ci.yml	Removed recursive submodule checkout and added Bazel version matrix testing

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[GuillaumeLagrange]

olgtm, have we tested on workerd ?

Also, AFAI understand, ci did not fail because we were fetching with the submodule, so
--incompatible_disallow_empty_glob was not triggered right ?

[anonrig]

I recommend updating Bazel to the latest version as well (in bazel version file)

[anonrig]

olgtm, have we tested on workerd ?

Also, AFAI understand, ci did not fail because we were fetching with the submodule, so --incompatible_disallow_empty_glob was not triggered right ?

It didn't probably catch it because bazel version used in this repository is 7, not 8.

[GuillaumeLagrange]

olgtm, have we tested on workerd ?
Also, AFAI understand, ci did not fail because we were fetching with the submodule, so --incompatible_disallow_empty_glob was not triggered right ?

It didn't probably catch it because bazel version used in this repository is 7, not 8.

Yeah, but we do have a .bazelrc rule to explicitly enable this error, because we had the issue in the past 🤔