local_crate_repository: mark non-reproducible on Windows

Bazel >= 9.0.1 replants workspace-pointing symlinks as relative
`..\_main\...` paths when placing reproducible repos in the contents
cache. On Windows those paths resolve at `<output_base>/external/<repo>`
but dangle from `<output_base>/execroot/_main/external/<repo>` (there
is no `execroot/_main/external/_main`), so actions fail to read the
crate sources.

Marking the repo non-reproducible on Windows skips the replanting, so
the original absolute symlinks survive and resolve from both views. The
tradeoff is loss of remote-repo-contents-cache eligibility on Windows.

See bazelbuild/bazel#29515.

Author: walter-zeromatter

rs/private/crate_repository.bzl

@@ -98,8 +98,16 @@ def _local_crate_repository_impl(rctx):
 
     rctx.file("BUILD.bazel", _generate_build_file(rctx, cargo_toml))
 
+    # On Windows, Bazel >= 9.0.1 replants workspace symlinks as relative
+    # `..\_main\...` paths before placing reproducible repos in the contents
+    # cache. Those resolve at the output_base but dangle from the action
+    # execroot (there is no `execroot/_main/external/_main`). Marking the
+    # repo non-reproducible on Windows skips the replanting and keeps the
+    # original absolute symlinks, which resolve from both paths.
+    # See https://github.com/bazelbuild/bazel/issues/29515.
+    is_windows = rctx.os.name.lower().startswith("windows")
     return rctx.repo_metadata(
-        reproducible = bazel_features.external_deps.repo_rules_relativize_symlinks,
+        reproducible = bazel_features.external_deps.repo_rules_relativize_symlinks and not is_windows,
     )
 
 local_crate_repository = repository_rule(