Mirrors for gnu.org and kernel.org

[fredowski]

The CI build of yosys #7719 fails because several packages are sourced from gnu.org and kernel.org. All ai crawlers in this world are permanently downloading gnu.org:

https://www.fsf.org/bulletin/2025/spring/defending-savannah-from-ddos-attacks

buildkite doing serious business also means huge numbers of attempts to download from gnu.org and kernel.org. So buildkite ends up in the tarpit and the CI never succeeds because the downloads fail.

I suggest that buildkite sets up mirrors for gnu.org and kernel.org to relieve these projects from the massive download attempts from buildkite. @hzeller, @fmeum, @meteorcloudy, @fweikert Is there maybe somebody from openroad/google who knows somebody from buildkite to discuss this idea?

[fmeum]

Cloudflare set up a mirror for BCR source archives that you can use via --module_mirrors=bcr.cloudflaremirrors.com.

[meteorcloudy]

Should we add this in our documentation?

[fredowski]

I tried this in the Yosys CI by adding the parameter. Unfortunately bazel 7.x does not know this parameter and errors. Bazel 8 and 9 still try to download from gnu:

20:35:28) WARNING: For repository 'rules_python', the root module requires module version rules_python@1.5.1, but got rules_python@1.7.0 in the resolved dependency graph. Please update the version in your MODULE.bazel or set --check_direct_dependencies=off
(20:36:31) WARNING: Download from https://mirrors.kernel.org/gnu/m4/m4-1.4.18.tar.xz failed: class java.io.IOException Connect timed out
(20:37:26) WARNING: Download from https://ftp.gnu.org/gnu/m4/m4-1.4.18.tar.xz failed: class java.io.IOException Connect timed out
(20:37:26) INFO: Repo rules_m4++default_toolchain_ext+m4_v1.4.18 defined by rule m4_repository in @@rules_m4+//m4/rules:m4_repository.bzl
(20:37:26) ERROR: /Users/buildkite/Library/Caches/bazel/_bazel_buildkite/6e473669a5d4e06d27b57c3cc9fa76a9/external/rules_m4+/m4/rules/m4_repository.bzl:83:29: An error occurred during the fetch of repository 'rules_m4++default_toolchain_ext+m4_v1.4.18':
   Traceback (most recent call last):
	File 

See the ci build logs: https://buildkite.com/bazel/bcr-presubmit/builds/30141/steps/canvas?sid=019ce388-1b26-46df-ba41-5d775133fa9f