pantsbuild / pants / 35612
0%
main: 93%

LAST BUILD BRANCH: feat-configurable-nailgun-jar
DEFAULT BRANCH: main
Ran
Jobs 1
Files 439
Run time 48s
Badge
Embed ▾
README BADGES
x

If you need to use a raster PNG badge, change the '.svg' to '.png' in the link

Markdown

Textile

RDoc

HTML

Rst
35612

push

travis-ci-com

web-flow 
Improve support of MyPy requirements when Python 2 used (#10853)

### Problem

The wheels used by third-party code might not use the same constraints as what the MyPy Pex uses. This was causing errors (https://github.com/pantsbuild/pants/issues/10819), which we fixed in https://github.com/pantsbuild/pants/pull/10820.

However, that fix was not perfect. Even if there were valid typed Python 2 wheels, we would ignore them. WIth Python 3, we had to be careful that `mypy.pex` used the exact same constraints as `requirements.pex`, so that, for example, we don't run MyPy with Py36 but resolve requirements with Py37.

### Solution

Stop using `--pex-path` to join the `requirements.pex`, which has the effect of the wheels being put on `PYTHONPATH`. (We were then teaching MyPy to read from this PYTHONPATH through a custom launcher script.)

Instead, we extract the wheel folders from `requirements.pex`, and teach our custom launcher script to look in these extracted `.deps/` folders through a new `EXTRACTED_WHEELS` env var. MyPy will use this to resolve the requirements, without us actually including the wheels in the final PEX or modifying PYTHONPATH.

### Result

Our Python 2 test now fully works, even though one of the wheels is not compatible with Python 3.

We no longer need to align `mypy.pex` with `requirements.pex`.

#### Caveat: MyPy plugins must be installed with `--mypy-extra-requirements`

An initial implementation did not use `EXTRACTED_WHEELS` and instead loaded the wheels via `PYTHONPATH`. This allowed for you to specify MyPy plugins via normal dependencies on `python_requirement_library` targets, because that requirement would get loaded via PYTHONPATH. Now, you cannot do this; you must specify the requirement via `--mypy-extra-requirements`.

This caveat seems acceptable. For Pytest, it's convenient that we allow you to load plugins via normal requirements, as it allows you to only sometimes use the plugin. MyPy is much mo... (continued)

0 of 29554 relevant lines covered (0.0%)

0.0 hits per line

Jobs
ID Job ID Ran Files Coverage
5 35612.5 (PANTS_CONFIG_FILES="${TRAVIS_BUILD_DIR}/pants.travis-ci.toml" PANTS_DYNAMIC_UI=false LC_ALL="en_US.UTF-8" AWS_BUCKET=ci-public.pantsbuild.org BOOTSTRAPPED_PEX_KEY_PREFIX=daily/${TRAVIS_BUILD_NUMBER}/${TRAVIS_BUILD_ID}/pants.pex NATIVE_ENGINE_SO_KEY_PREFIX=monthly/native_engine_so PYENV_PY27_VERSION=2.7.18 PYENV_PY36_VERSION=3.6.10 PYENV_PY37_VERSION=3.7.7 PYENV_PY38_VERSION=3.8.3 PYENV_ROOT_OSX=${HOME}/.pants_pyenv PYENV_ROOT="${PYENV_ROOT:-${PYENV_ROOT_OSX}}" PATH="${PYENV_ROOT}/shims:${PATH}" AWS_CLI_ROOT="${HOME}/.aws_cli" AWS_ACCESS_KEY_ID__TO_BE_REEXPORTED_ON_DEPLOYS=AKIAV6A6G7RQ2HFZ5KP7 AWS_SECRET_ACCESS_KEY=[secure] RUST_BACKTRACE="all" BOOTSTRAPPED_PEX_KEY_SUFFIX=py36.linux PANTS_REMOTE_CA_CERTS_PATH=/usr/lib/google-cloud-sdk/lib/third_party/grpc/_cython/_credentials/roots.pem CACHE_NAME=python_tests.py36) 0
0.0
 Travis Job 35612.5
Source Files on build 35612
Detailed source file information is not available for this build.