Python

pip, poetry, venv, and pytest failures - fixed.

Fix Python CI failures: pip install errors, dependency resolution conflicts, virtual environment problems, build backend errors, and pytest collection failures across pip and poetry.

pip & dependencies

Resolution conflicts, wheels, and build isolation.

"--no-build-isolation" buildFix a "pip install --no-build-isolation" failure in CI - disabling isolation means the build backend and its "Could not build wheels for cffi"Fix pip "Could not build wheels for cffi" in CI - the C foreign function interface build needs a compiler and "could not build wheels"Fix pip "ERROR: Could not build wheels for X, which is required to install pyproject.toml-based projects" in "Failed building wheel"Fix pip "ERROR: Failed building wheel for <pkg>" in CI - when there is no prebuilt wheel and the source build "does not support editable"Fix pip "ERROR: Project file:///... does not support editable installs" / "build_editable not supported" in "ReadTimeoutError"Fix transient pip "ReadTimeoutError" and "Connection broken" failures in CI - network blips and slow PyPI "lock file is not up to date"Fix Poetry "pyproject.toml changed significantly since poetry.lock was last generated" in CI - regenerate and Poetry keyring backendFix Poetry keyring failures and hangs in CI - "Failed to create the collection: Prompt dismissed" or a "FileNotFoundError" (subprocess)Fix subprocess.run() "FileNotFoundError: [Errno 2] No such file or directory: 'cmd'" in CI - the program

Environments & versions

venv, interpreter mismatches, and PATH.

"Couldn't parse '.coverage'"Fix coverage "Couldn't parse '.coverage'" during combine in CI - a data file is corrupt, empty, or from an "uvicorn: command not found"Fix "uvicorn: command not found" in CI - the ASGI server is not installed in the active environment, or its "does not appear to be a Python project"Fix pip "ERROR: file://... does not appear to be a Python project" in CI - pip was pointed at a directory "BaseSettings has been moved"Fix the Pydantic v1-to-v2 "BaseSettings has been moved to pydantic-settings" error in CI - settings classes "python: command not found"Fix "python: command not found" in CI - the binary is named python3, the interpreter is not on PATH, or

Build & native

Compiling C extensions and missing headers.

Cython compile errorFix Cython compile failures in CI - "Cython not found" in the build env, a stale .c file regenerated against flit build errorFix flit build "Cannot package module without a version" / "Missing docstring" in CI - flit reads __version__ maturin build errorFix maturin build failures in CI - "cargo not found", a PyO3 ABI mismatch, or a missing Rust toolchain when "build backend" import failsFix pip "Cannot import 'setuptools.build_meta'" / build-backend errors in CI - caused by build isolation "gcc failed: No such file or directory"Fix "error: command 'gcc' failed: No such file or directory" in CI - the runner has no C compiler installed, "partially initialized module (circular import)"Fix "ImportError: cannot import name X from partially initialized module Y (most likely due to a circular "libGL.so.1: cannot open shared object file"Fix "ImportError: libGL.so.1: cannot open shared object file" in CI - a Python wheel needs a system library "dictionary changed size during iteration"Fix "RuntimeError: dictionary changed size during iteration" in CI - code added or removed keys from a dict "SSLCertVerificationError" (requests)Fix "ssl.SSLCertVerificationError: certificate verify failed" from requests in CI - the runner could not "can't pickle" in multiprocessingFix "TypeError: cannot pickle X" / "PicklingError" in CI - multiprocessing must pickle the target and its "undefined symbol" (torch ABI)Fix torchvision/torchaudio "undefined symbol" ImportError in CI - the extension was compiled against a

pytest & tooling

Collection errors, imports, and exit codes.

"There is no current event loop"Fix "RuntimeError: There is no current event loop in thread" in CI - an async FastAPI test ran without "Cannot find implementation or library stub"Fix mypy "Cannot find implementation or library stub for module" in CI - mypy cannot locate a module or its "--import-mode" import errorsFix test import failures after switching pytest "--import-mode" in CI - importlib mode does not add rootdir "Failed: DID NOT RAISE"Fix pytest "Failed: DID NOT RAISE <Exception>" in CI - a pytest.raises block expected an exception that the "import file mismatch"Fix pytest "import file mismatch" in CI - two test files share a module name without packages, or stale "ImportError while importing test module"Fix pytest "ImportError while importing test module" in CI - a test file failed to import, often from a "no tests ran" (exit 5)pytest exit code 5 means no tests were collected, not that tests passed. pytest-cov 0% coverageFix pytest-cov measuring nothing in CI - "--cov" set to the wrong path, an editable/installed package "-n auto" zero workersFix pytest-xdist "-n auto" resolving to 0 workers in CI - a container reporting 1 CPU, or all collection "worker crashed"Fix pytest-xdist "node down: Not properly terminated" / "replacing crashed worker" in CI - a segfault, OOM

Explore other topics

GitHub ActionsWorkflow, runner, and YAML errors - diagnosed and fixed. Node.js & npmnpm, yarn, and pnpm failures in CI - solved. DockerBuild, run, compose, and registry errors - explained. Java & JVMMaven, Gradle, and JVM failures in CI - resolved. GoGo build, module, and test failures - diagnosed. RustCargo and toolchain failures in CI - fixed.