[Bug]: spurious write_source_file test failures with RBE

[shahms]

What happened?

I have a bit of an awkward vendoring setup where we want to copy remote protocol buffer files to the local source tree and commit the generated Go alongside it (so the repository can be built via go build). This mostly works fine, except I occasionally see (apparently) spurious test failures when using RBE to build the test. Specifically, I see:

INFO: From Testing //third_party/bazel:proto_srcs_sync_test:
==================== Test output for //third_party/bazel:proto_srcs_sync_test:
ERROR: cannot compare a directory "third_party/bazel/proto_srcs" against a file "third_party/bazel/src"
================================================================================

The test runs fine if built locally (surviving even a bazel clean) and when manually inspecting the files in question in the execroot, both appear to be directories and not files.

Version

Development (host) and target OS/architectures:
Debian rodete-based Linux distribution

Output of bazel --version: bazel 6.2.0

Version of the Aspect rules, or other relevant rules from your
WORKSPACE or MODULE.bazel file:

http_archive(
    name = "aspect_bazel_lib",
    sha256 = "d488d8ecca98a4042442a4ae5f1ab0b614f896c0ebf6e3eafff363bcc51c6e62",
    strip_prefix = "bazel-lib-1.33.0",
    url = "https://github.com/aspect-build/bazel-lib/releases/download/v1.33.0/bazel-lib-v1.33.0.tar.gz",
)

load("@aspect_bazel_lib//lib:repositories.bzl", "aspect_bazel_lib_dependencies")

aspect_bazel_lib_dependencies()

Language(s) and/or frameworks involved:

How to reproduce

It's really (frustatingly) inconsistent. I have nearly identical setup for Rust protobufs that has never exhibited the behavior. But the BUILD snippet which causes problems is:


copy_to_directory(
    name = "proto_srcs",
    srcs = [
        # We need to include the Gazelle-generated BUILD files in the original bundle to avoid test failures.
        "//third_party/bazel/src/main/java/com/google/devtools/build/lib/buildeventstream/proto:BUILD",
        "//third_party/bazel/src/main/java/com/google/devtools/build/lib/packages/metrics:BUILD",
        "//third_party/bazel/src/main/protobuf:BUILD",
        "@io_bazel_files//:proto_srcs",
    ],
    include_external_repositories = ["io_bazel_files"],
    replace_prefixes = {
        "src/": "",
        "third_party/bazel/": "",
    },
    visibility = ["//visibility:private"],
)

write_source_file(
    name = "proto_srcs_sync",
    in_file = ":proto_srcs",
    out_file = "src",
    visibility = ["//visibility:private"],
)

### Any other information?

_No response_

[mattem]

Fixed by #531