Cache miss even tho key exists

We’re using actions/cache@v3 in self-hosted runners (ubuntu-based).

We get a cache hit in one branch:

Cache restored successfully
Cache restored from key: v16.15.0-nodemodules-91bd5669329abf8e285e2b706e76bc9787848689b31ec5755f991616af28e407

Then, roughly an hour later, in a different branch (same workflow), we get a cache miss for the same key:

Cache not found for input keys: v16.15.0-nodemodules-91bd5669329abf8e285e2b706e76bc9787848689b31ec5755f991616af28e407

Why?

No other workflow runs took place between them.

This is the action we’re using:

name: 'Install Node dependencies'
description: 'Install Node dependencies'
author: 'proxyco'

inputs:
  path:
    default: '.'
    description: 'Location of node_modules'
    required: false
  node-version:
    description: 'The Node version'
    required: true

runs:
  using: "composite"
  steps:
    - name: Cache node_modules
      id: node-modules
      uses: actions/cache@v3
      with:
        path: ${{ inputs.path }}/node_modules
        key: ${{ inputs.node-version }}-nodemodules-${{ hashFiles(format('{0}/package-lock.json', inputs.path)) }}

    - name: Install dependencies
      if: steps.node-modules.outputs.cache-hit != 'true'
      # Skip post-install scripts here, as a malicious
      # script could steal NODE_AUTH_TOKEN.
      run: npm ci --ignore-scripts
      shell: bash
      working-directory: ${{ inputs.path }}

usage:

      - name: Set Node version
        run: echo ::set-output name=NODE_VERSION::$(node --version)
        id: nvm

      - name: Install dependencies
        uses: ./.github/actions/npm-install
        with:
          node-version: ${{ steps.nvm.outputs.NODE_VERSION }}

[vsvipul]

@BeyondEvil Yes, this is expected. You will get a cache miss on a different branch if the cache save happened on a different branch with the same key, unless the save happens in the main/master branch, in which case all the other branches can access it. Please let me know if you have any more questions.

[aminya]

Secondly, here’s some info on Cache scopes, it is not a bug, rather a feature.

Not a good feature. It is undermining GitHub’s biggest feature which is making a pull request.

https://github.com/actions/cache/issues/79#issuecomment-1204808650