black aborted under pre-commit

[RonnyPfannschmidt]

on a repo i cant share publically we have a linting stage that invokes black via pre-commit

on occasion we observe an "aborted" from black in that pileline,

resulting in output like

$ pre-commit run --all
[INFO] Initializing environment for https://github.com/asottile/reorder_python_imports.
[INFO] Initializing environment for https://github.com/ambv/black.
[INFO] Initializing environment for https://github.com/pre-commit/pre-commit-hooks.
[INFO] Initializing environment for https://github.com/asottile/pyupgrade.
[INFO] Installing environment for https://github.com/asottile/reorder_python_imports.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/asottile/pyupgrade.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/pre-commit/pre-commit-hooks.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/ambv/black.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
Reorder python imports...................................................Passed
black....................................................................Failed
hookid: black

Aborted!

Trim Trailing Whitespace.................................................Passed
Fix End of Files.........................................................Passed
Check Yaml...............................................................Passed
Debug Statements (Python)................................................Passed
Flake8...................................................................Passed
pyupgrade................................................................Passed

the pre-commit configuration is

repos:
- repo: https://github.com/asottile/reorder_python_imports
  rev: v1.3.3
  hooks:
  - id: reorder-python-imports
    language_version: python3
- repo: https://github.com/ambv/black
  rev: 18.9b0
  hooks:
  - id: black
    args: [--safe, --quiet, --line-length, "100"]
    language_version: python3
- repo: https://github.com/pre-commit/pre-commit-hooks
  rev: v2.0.0
  hooks:
  - id: trailing-whitespace
    language_version: python3
  - id: end-of-file-fixer
    language_version: python3
  - id: check-yaml
    language_version: python3
  - id: debug-statements
    language_version: python3
  - id: flake8
    language_version: python3
- repo: https://github.com/asottile/pyupgrade
  rev: v1.10.1
  hooks:
  - id: pyupgrade
    language_version: python3

the error only crops up on rare occasions and i would appreciate suggestions for better debugging
we are running it under a gitlab ci runner

cc @asottile

[asottile]

This is fixed on master but there hasn't been a release.

#673 (comment) outlines the workaround until black makes a tagged release (or you can pre-commit autoupdate --bleeding-edge https://github.com/ambv/black)

[asottile]

#674 and #675 contained the fixes

[RonnyPfannschmidt]

@asottile awesome, thanks for the swift answer