fix: Only enable path mapping if supported

[fmeum]

#1217 unconditionally enabled support for path mapping for rules that may use location expansion or hardcode paths in other ways. Instead, only enable it when it is clearly safe to do so.

Verified manually by running bazel test //... --experimental_output_paths=strip.

Work towards cerisier/toolchains_llvm_bootstrapped#334

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Bazel 8 (Test)

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137 tests (100.0%) were fully cached saving 16s.

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Bazel 9 (Test)

2 test targets passed

Targets

//lib/tests/copy_to_directory:case_22_test [k8-fastbuild]                    68ms
//lib/tests/copy_to_directory_bin_action:test [k8-fastbuild]                 68ms

Total test execution time was 136ms. 135 tests (98.5%) were fully cached saving 18s.

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Bazel 7 (Test)

e2e/api_entries

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Bazel 8 (Test)

e2e/api_entries

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Bazel 9 (Test)

e2e/api_entries

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1 test (100.0%) was fully cached saving 50ms.

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Bazel 7 (Test)

e2e/copy_action

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1 test (100.0%) was fully cached saving 31ms.

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Bazel 8 (Test)

e2e/copy_action

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1 test (100.0%) was fully cached saving 26ms.

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Bazel 9 (Test)

e2e/copy_action

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1 test (100.0%) was fully cached saving 32ms.

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Bazel 7 (Test)

e2e/copy_to_directory

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6 tests (100.0%) were fully cached saving 297ms.

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Bazel 8 (Test)

e2e/copy_to_directory

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Bazel 9 (Test)

e2e/copy_to_directory

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6 tests (100.0%) were fully cached saving 349ms.

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e2e/coreutils

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e2e/coreutils

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e2e/coreutils

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e2e/external_copy_to_directory

All tests were cache hits

1 test (100.0%) was fully cached saving 31ms.

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Bazel 8 (Test)

e2e/external_copy_to_directory

Buildkite build #450 is running...

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e2e/external_copy_to_directory

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e2e/smoke

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e2e/smoke

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e2e/smoke

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Bazel 7 (Test)

e2e/write_source_files

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1 test (100.0%) was fully cached saving 39ms.

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Bazel 8 (Test)

e2e/write_source_files

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1 test (100.0%) was fully cached saving 33ms.

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Bazel 9 (Test)

e2e/write_source_files

All tests were cache hits

1 test (100.0%) was fully cached saving 40ms.

[Copilot]

Pull request overview

This PR refines the path mapping support that was unconditionally enabled in PR #1217. It makes path mapping conditional, only enabling it when actions don't use location/make variable expansion or embed paths in configuration files or environment variables. This ensures compatibility with Bazel's --experimental_output_paths=strip flag.

Changes:

• Added conditional path mapping to run_binary and expand_template rules based on whether expansion occurs
• Removed path mapping support from copy_to_directory due to paths embedded in JSON config
• Renamed COPY_EXECUTION_REQUIREMENTS to SUPPORTS_PATH_MAPPING for clarity

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
lib/private/copy_common.bzl	Renamed constant from COPY_EXECUTION_REQUIREMENTS to SUPPORTS_PATH_MAPPING for better clarity
lib/private/copy_file.bzl	Updated to use renamed constant; continues to support path mapping
lib/private/copy_directory.bzl	Updated to use renamed constant; continues to support path mapping
lib/private/copy_to_directory.bzl	Removed path mapping support and added TODO comment explaining the JSON config prevents path mapping
lib/private/expand_template.bzl	Added logic to conditionally enable path mapping only when substitutions don't use expansion
lib/private/run_binary.bzl	Added logic to conditionally enable path mapping based on args/env expansion and stamping usage

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[fmeum]

@alexeagle Could you cut a release with this change?