File corruption via `CopyFile` action

We noticed two cases where instead of proper files, we got files with the expected size, but just null bytes as their content after a copy operation using `CopyFile`. In both cases, this happened for protobuf compilation via rules_proto_grpc, which depends on the old aspect_bazel_lib 2.x releases.
`CopyFile` for the 2.x releases references coreutils version 0.1.0 instead of 0.5.0. We patched aspect_bazel_lib locally to use 0.5.0 for now, but I am wondering whether I should open a pull request to update aspect_bazel_lib to coreutils 0.5.0 or 0.9.0. For bazel_lib, I have already opened https://github.com/bazel-contrib/bazel-lib/pull/1270.

I unfortunately don't have a reliable reproducer to confirm that coreutils 0.5.0 or 0.9.0 properly fix the underlying root cause.

Start at the CopyFile action and inspect how aspect_bazel_lib 2.x references coreutils 0.1.0, comparing it with 0.5.0 and 0.9.0. Reproduce the protobuf compilation case through rules_proto_grpc if possible, and consider it done when copied files contain their expected data rather than null bytes.

Written by the indexing model from the issue text.