Break mutual dependency between please_pex and test runners#266
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chrisnovakovic merged 1 commit intoplease-build:masterfrom Oct 27, 2025
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The please_pex tool depends on various third-party modules for the built-in test runner bootstraps, which in turn require please_pex in order to be built. This circular dependency prevents the plugin from being built entirely from source - see please-build#265. The root cause of this circular dependency is the presence of the entry points in `//third_party/python:{behave,pytest}` - `python_wheel` doesn't require please_pex per se, but the use of the `binary` or `entry_points` parameters results in `python_binary` being used to build the outputs, which does require please_pex in order to make them executable. The entry points aren't actually necessary on these targets, though, because the generated .pex files aren't executed directly - they are just unzipped and concatenated onto the please_pex binary to form the bootstrap archive containing the built-in test runners and their transitive dependencies. Remove the `entry_points` parameters from the behave and pytest targets, and refactor the `//tools/please_pex` dependency tree so that the test runners and all of their transitive dependencies are present when the bootstrap archive is concatenated onto the main please_pex binary. The bootstrap archive's contents remain the same, with the following omissions: - `.bootstrap/plz.py` - This is written by please_pex when creating an executable .pex - its presence isn't meaningful or required in the bootstrap archive. - `.bootstrap/py/_vendored_packages/apipkg-2.0.0.dist-info/__init__.py` - `.bootstrap/py/_vendored_packages/iniconfig-1.1.1.dist-info/__init__.py` - These empty files were created by please_pex when creating the executable .pex for pytest - their presence isn't meaningful or required in the bootstrap archive. Fixes please-build#265.
toastwaffle
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chrisnovakovic
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The circular dependency between please_pex and its bootstrap archive was broken in please-build#266, allowing for the plugin to be configured to use `//tools_please_pex` as its own pex tool. This is simpler than building the please_pex binary in one step, copying it elsewhere in the file system for persistence, then configuring future steps to use that binary as the pex tool.
chrisnovakovic
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The circular dependency between please_pex and its bootstrap archive was broken in #266, allowing for the plugin to be configured to use `//tools/please_pex` as its pex tool. This is simpler than building the please_pex binary in one step, copying it elsewhere in the file system for persistence, then configuring future steps to use that binary as the pex tool.
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The please_pex tool depends on various third-party modules for the built-in test runner bootstraps, which in turn require please_pex in order to be built. This circular dependency prevents the plugin from being built entirely from source - see #265.
The root cause of this circular dependency is the presence of the entry points in
//third_party/python:{behave,pytest}-python_wheeldoesn't require please_pex per se, but the use of thebinaryorentry_pointsparameters results inpython_binarybeing used to build the outputs, which does require please_pex in order to make them executable. The entry points aren't actually necessary on these targets, though, because the generated .pex files aren't executed directly - they are just unzipped and concatenated onto the please_pex binary to form the bootstrap archive containing the built-in test runners and their transitive dependencies.Remove the
entry_pointsparameters from the behave and pytest targets, and refactor the//tools/please_pexdependency tree so that the test runners and all of their transitive dependencies are present when the bootstrap archive is concatenated onto the main please_pex binary.The bootstrap archive's contents remain the same, with the following omissions:
.bootstrap/plz.py.bootstrap/py/_vendored_packages/apipkg-2.0.0.dist-info/__init__.py.bootstrap/py/_vendored_packages/iniconfig-1.1.1.dist-info/__init__.pyFixes #265.