Fix `qmk find` failure due to circular imports (#22523)
There was an import cycle in the Python modules:
- `qmk.build_targets` imported `qmk.cli.generate.compilation_database`;
- importing `qmk.cli.generate.compilation_database` requires
initializing `qmk.cli` first;
- the initialization of `qmk.cli` imported the modules for all CLI
commands;
- `qmk.cli.compile` imported `qmk.build_targets`.
This cycle did not matter in most cases, because `qmk.cli` was imported
first, and in that case importing `qmk.cli.generate.compilation_database`
did not trigger the initialization of `qmk.cli` again. However, there was
one corner case when `qmk.bulld_targets` was getting imported first:
- The `qmk find` command uses the `multiprocessing` module.
- The `multiprocessing` module uses the `spawn` start method on macOS
and Windows.
- When the `spawn` method is used, the child processes initialize
without any Python modules loaded, and the required modules are loaded
on demand by the `pickle` module when receiving the serialized objects
from the main process.
The result was that the `qmk find` command did not work properly on macOS
(and probably Windows too); it reported exceptions like this:
ImportError: cannot import name 'KeyboardKeymapBuildTarget' from partially initialized module 'qmk.build_targets' (most likely due to a circular import)
Moving the offending `qmk.cli.generate.compilation_database` import into
the method which actually uses it fixes the problem.
1 files changed, 1 insertions(+), 1 deletions(-) M lib/python/qmk/build_targets.py
M lib/python/qmk/build_targets.py => lib/python/qmk/build_targets.py +1 -1
@@ 10,7 10,6 @@ from qmk.constants import QMK_FIRMWARE, INTERMEDIATE_OUTPUT_PREFIX from qmk.commands import find_make, get_make_parallel_args, parse_configurator_json from qmk.keyboard import keyboard_folder from qmk.info import keymap_json from qmk.cli.generate.compilation_database import write_compilation_database class BuildTarget: @@ 105,6 104,7 @@ class BuildTarget: def generate_compilation_database(self, build_target: str = None, skip_clean: bool = False, **env_vars) -> None: self.prepare_build(build_target=build_target, **env_vars) command = self.compile_command(build_target=build_target, dry_run=True, **env_vars) from qmk.cli.generate.compilation_database import write_compilation_database # Lazy load due to circular references write_compilation_database(command=command, output_path=QMK_FIRMWARE / 'compile_commands.json', skip_clean=skip_clean, **env_vars) def compile(self, build_target: str = None, dry_run: bool = False, **env_vars) -> None: