I’ve removed TensorFlow’s dependency on tensorflow/toolchains by integrating it back into TensorFlow. This is relevant to you if your bazel WORKSPACE imports org_tensorflow or tf_toolchains, and will take effect once you upgrade your org_tensorflow repository to a commit newer than today, 2022-02-15. The new location is //tensorflow/tools/toolchains.
We did this because the split into a separate repository failed to remove the dependency on TensorFlow, and the tight coupling of the two repositories was causing a lot of busywork without notable benefits.
If you are importing org_tensorflow and loading toolchains with the workspace.bzl files (most users do this), I expect this to be a no-op for you. TensorFlow’s toolchains dependency was and still is entirely handled by those workspace files. If you are importing tf_toolchains manually, you can remove the import only after updating org_tensorflow to a date newer than today, 2022-02-15. The only trouble we’ve run into so far is that the toolchains repository contains some not-always-valid BUILD files, so if you are running builds on //tensorflow/..., you may need to exclude the //tensorflow/tools/toolchains/... packages.
I am planning to request archival of tensorflow/toolchains soon, which also should not break any of your workflows.