v3.12

What's Changed

• Update the manifest by @DilumAluthge in #81
• Add the optional --arch command-line argument to the test_rootfs.jl script by @DilumAluthge in #82
• CI: Add a basic whitespace check by @DilumAluthge in #83
• README: add a link to the base-buildkite-docs repository by @DilumAluthge in #86

Full Changelog: v3.11...v3.12