This is what I cam up with. It is used in the repository of the Math-RPN module.

examples/workflows/perl-os-matrix-show-logs.yml

name: CI

on:
    push:
        branches: '*'
    pull_request:
        branches: '*'

jobs:
  perl-job:
    strategy:
      fail-fast: false
      matrix:
        runner: [ubuntu-latest, macos-latest, windows-latest]
        perl: [ '5.32', '5.30' ]

    runs-on: ${{matrix.runner}}
    name: OS ${{matrix.runner}} Perl ${{matrix.perl}}

    steps:
    - uses: actions/checkout@v2

    - name: Set up perl
      uses: shogo82148/actions-setup-perl@v1
      with:
          perl-version: ${{ matrix.perl }}
          #distribution: strawberry

    - name: Install dependencies
      run: |
          cpanm --notest Module::Install
          cpanm --installdeps --notest .

    - name: Show content of log files on Linux
      if: ${{ failure() && startsWith( matrix.runner, 'ubuntu-' )  }}
      run: cat /home/runner/.cpanm/work/*/build.log

    - name: Show content of log files on Mac
      if: ${{ failure() && startsWith( matrix.runner, 'macos-' )  }}
      run: cat /Users/runner/.cpanm/work/*/build.log

    - name: Show content of log files on Windows
      if: ${{ failure() && startsWith( matrix.runner, 'windows-' )  }}
      run: cat C:/Users/RUNNER~1/.cpanm/work/*/build.log

    - name: Regular Tests
      run: |
          perl Makefile.PL
          make
          make test

The thing that is new here, compared to the annotated example is that we have 3 conditional steps. They all run only if one of the previous steps failed. Each one will run on a particular Operating system.

Each one will show the content of all the log-files created by cpanm in the respecive location on the specific Operating System.

The actual running of the tests come after it as we don't want to see the installation logs if the problem was only in running our own tests.

We also had to install Module::Install before we tried to install any of our dependencies as that's what developers who use Module::Install need to do.

Actually the use of Module::Install is discouraged by its current maintainer, but if you are already using it and don't want to change it now, then this is what you need to do.