no such package '@@bazel_tools//platforms' in bazel build

[simonff]

Hi! I'm trying to follow the process we recommend to the external users of our repo, but I'm running into problems.

If I git clone [https://github.com/google/earthengine-catalog](https://github.com/google/earthengine-catalog%60), remove .bazelversion that pins bazel to an old version, and then run bazel build --define jsonnet_port=cpp //... in the top directory, I get:

ERROR: no such package '@@bazel_tools//platforms': BUILD file not found in directory 'platforms' of external repository @@bazel_tools. Add a BUILD file to a directory to mark it as a package.

This is probably due to the jsonnet_to_json rule that we load here, but I don't understand enough how bazel+jsonnet work together to ask a more intelligent question.