EnvironmentFileOverwritten

Environment files should be appended.

Defined by EnvironmentFileOverwriteRule which supports workflows, actions in the "Default" ruleset.

Description

Most environment files are used to pass data between steps, and should be appended to, not overwritten.

It is a common mistake to overwrite environment files, which can lead to data loss or unexpected behavior.

Use >> instead of >, to ensure the file is appended, not overwritten.

References:

• Environment files documentation

Compliant example

Appending to an environment file is usually the intended behavior.

example.yml

on: push
jobs:
  example:
    runs-on: ubuntu-latest
    steps:
      - run: echo "result=Example" >> $GITHUB_OUTPUT

Non-compliant example

Overwriting an environment file is probably unintended.

example.yml

on: push
jobs:
  example:
    runs-on: ubuntu-latest
    steps:
      - run: echo "result=Example" > $GITHUB_OUTPUT

• Line 6: Step[#0] in Job[example] overwrites environment file GITHUB_OUTPUT.