SIGSEGV when Python tests use the `ctypes` module

Description:

When using the Python installed with this action I run into SIGSEGV on Linux if my tests use ctypes. This is is the offending workflow

name: Tests
on: push
concurrency: 
  group: ${{ github.head_ref || github.run_id }}
  cancel-in-progress: true
jobs:
  tests-linux:
    runs-on: ubuntu-latest
    
    strategy:
      fail-fast: false
      matrix:
        python-version: ["2.7", "3.5", "3.6", "3.7", "3.8", "3.9", "3.10", "3.11"]
    
    env:
      AUSTIN_TESTS_PYTHON_VERSIONS: ${{ matrix.python-version }}
    
    name: Tests on Linux with Python ${{ matrix.python-version }}
    steps:
      - uses: actions/checkout@v2

      - name: Install build dependencies
        run: |
          sudo apt-get -y install libunwind-dev binutils-dev libiberty-dev

      - name: Install test dependencies
        run: |
          sudo apt-get -y install \
            valgrind \
            gdb

      - name: Install Python
        uses: actions/setup-python@v4
        with:
          python-version: ${{ matrix.python-version }}

      - name: Install Python 3.10
        uses: actions/setup-python@v4
        with:
          python-version: "3.10"

      - name: Compile Austin
        run: |
          autoreconf --install
          ./configure --enable-debug-symbols true
          make

      - name: Run tests
        run: |
          ulimit -c unlimited
          python3.10 -m venv .venv
          source .venv/bin/activate
          pip install --upgrade pip
          pip install -r test/requirements.txt
          sudo -E .venv/bin/pytest --pastebin=failed --no-flaky-report -sr a -n auto
          .venv/bin/pytest --pastebin=failed --no-flaky-report -sr a -n auto
          deactivate

If Python is installed from, e.g., deadsnakes/ppa, then the tests pass without SIGSEGV. I can also get the tests to pass locally.

This is an example of a happy workflow that pulls Python from the PPA: https://github.com/P403n1x87/austin/runs/7046194671?check_suite_focus=true

This is a run with the action: https://github.com/P403n1x87/austin/runs/7045119660?check_suite_focus=true

This was discovered with this PR: https://github.com/P403n1x87/austin/pull/120/files

Action version:

v4

Platform:

• Ubuntu
• macOS
• Windows

Runner type:

• Hosted
• Self-hosted

Tools version:

Repro steps:

See description above

Expected behavior:

No SIGSEGV, like with the Pythons from the PPA.

Actual behavior:

SIGSEGV if ctypes is used

[dsame]

@P403n1x87 Status update.

The problem has been reproduced on simplified code:

def test_queue_item():
    value = C.malloc(16)
    C.free(value)

[dsame]

@P403n1x87 thanks a lot for the backtrace, now i see a SEGFAULT is caused by an instruction of from /lib/x86_64-linux-gnu/libffi.so.7

It is known problem: toolcache python is built against libffi.so.6 which does not exist in ubuntu-20.04

While we are providing the solution, please try to add the step installing libffi.so.6 before running tests as workaround

        - run: |
            curl -LO http://archive.ubuntu.com/ubuntu/pool/main/libf/libffi/libffi6_3.2.1-8_amd64.deb
            sudo dpkg -i libffi6_3.2.1-8_amd64.deb
            sudo ln -sf libffi.so.6.0.4 /usr/lib/x86_64-linux-gnu/libffi.so