Respectful code cleanup: rename `master` branch to `main`

[hlopko]

Same task with the same justification as bazelbuild/bazel#12200.

[aiuto]

I plan to rename several sites on Monday 2021-06-28. That way if there is any fallout from automatic processes with a stale branch name I can be available to fix or advise.

[aiuto]

The branch is renamed

[viblo]

I just installed Bazelisk, and then tried to build "mediapipe" project, which gives me 404. It seems like the branch renaming is the reason:

INFO: Repository rules_cc instantiated at:
/home/vb/code/gh/google/mediapipe/WORKSPACE:36:13: in
Repository rule http_archive defined at:
/home/vb/.cache/bazel/_bazel_vb/a41a00c949dc2b3a22fd05f82d8c05c2/external/bazel_tools/tools/build_defs/repo/http.bzl:336:31: in
WARNING: Download from https://github.com/bazelbuild/rules_cc/archive/master.zip failed: class com.google.devtools.build.lib.bazel.repository.downloader.UnrecoverableHttpException GET returned 404 Not Found
ERROR: An error occurred during the fetch of repository 'rules_cc':
Traceback (most recent call last):
File "/home/vb/.cache/bazel/_bazel_vb/a41a00c949dc2b3a22fd05f82d8c05c2/external/bazel_tools/tools/build_defs/repo/http.bzl", line 111, column 45, in _http_archive_impl
download_info = ctx.download_and_extract(
Error in download_and_extract: java.io.IOException: Error downloading [https://github.com/bazelbuild/rules_cc/archive/master.zip] to /home/vb/.cache/bazel/_bazel_vb/a41a00c949dc2b3a22fd05f82d8c05c2/external/rules_cc/temp15386256763950372734/master.zip: GET returned 404 Not Found
ERROR: While resolving toolchains for target //mediapipe/examples/desktop/hello_world:hello_world: com.google.devtools.build.lib.packages.RepositoryFetchException: no such package '@rules_cc//cc': java.io.IOException: Error downloading [https://github.com/bazelbuild/rules_cc/archive/master.zip] to /home/vb/.cache/bazel/_bazel_vb/a41a00c949dc2b3a22fd05f82d8c05c2/external/rules_cc/temp15386256763950372734/master.zip: GET returned 404 Not Found
ERROR: Analysis of target '//mediapipe/examples/desktop/hello_world:hello_world' failed; build aborted: com.google.devtools.build.lib.packages.RepositoryFetchException: no such package '@rules_cc//cc': java.io.IOException: Error downloading [https://github.com/bazelbuild/rules_cc/archive/master.zip] to /home/vb/.cache/bazel/_bazel_vb/a41a00c949dc2b3a22fd05f82d8c05c2/external/rules_cc/temp15386256763950372734/master.zip: GET returned 404 Not Found

[aiuto]

Yes. You would have to change that to main.zip.

But... I think that is the wrong solution as well. You should not build your projects against the head of any dependencies. Doing that gives control over what goes into your project to someone else. The best thing to do is reference a named release. Unfortunately there are none, #91 Without that, freezing to a commit that you have tested against is the next best fallback.

[viblo]

Seems like they fixed it now: google-ai-edge/mediapipe@374f5e2