ci: ensure Autotools configure is generated in C/C++ CI

[Copilot]

The C/C++ CI workflow fails on branches without a pre-generated configure script (job 54655044154 at cd8c4b6). Many Autotools-based projects only commit configure.ac and generate configure during build.

Changes

• Replace hardcoded ./configure step with conditional Autotools preparation that:

  • Runs existing configure if present
  • Falls back to autogen.sh if available
  • Falls back to autoreconf -i (installing autoconf/automake/libtool/pkg-config) if configure.ac or configure.in exists
  • Fails with diagnostic output if no Autotools entrypoint found

• Preserve all existing make / make check / make distcheck steps unchanged

- name: Prepare build (Autotools)
  run: |
    set -e
    if [ -f configure ]; then
      ./configure
    elif [ -f autogen.sh ]; then
      ./autogen.sh
    elif [ -f configure.ac ] || [ -f configure.in ]; then
      sudo apt-get update && sudo apt-get install -y autoconf automake libtool pkg-config build-essential
      autoreconf -i && ./configure
    else
      echo "No Autotools entrypoint found" >&2 && ls -la && exit 1
    fi

Note: This enforces Autotools. If the project uses CMake or another build system, the workflow requires further updates.

Original prompt

The repository's C/C++ CI workflow currently runs ./configure directly but many branches do not include a pre-generated configure script, causing the job to fail with: "./configure: No such file or directory" (see job 54655044154 logs). The workflow file that ran is .github/workflows/c-cpp.yml (ref: cd8c4b6).

Goal: Update the workflow to reliably build Autotools-based projects by generating configure when needed (autoreconf/autogen.sh) and installing required tools. Keep existing make / make check / make distcheck steps.

Required changes to implement in a new branch (suggested branch name: fix/ci-autotools):

1. Update .github/workflows/c-cpp.yml to replace the existing configure step (which runs "./configure") with a Prepare build (Autotools) step that:
   • Detects whether configure exists and runs it if present.
   • If autogen.sh exists, runs it.
   • If configure.ac or configure.in exists, installs necessary packages and runs autoreconf -i, then runs ./configure.
   • Prints the repository root listing and fails with a helpful message if no supported Autotools entrypoint is found.

Use the following shell snippet for the step content (preserve set -e so the job fails on error):

• name: Prepare build (Autotools)
  run: |
  set -e
  if [ -f configure ]; then
  echo "Running ./configure"
  chmod +x configure
  ./configure
  elif [ -f autogen.sh ]; then
  echo "Running ./autogen.sh"
  chmod +x autogen.sh
  ./autogen.sh
  elif [ -f configure.ac ] || [ -f configure.in ]; then
  echo "Running autoreconf -i"
  sudo apt-get update
  sudo apt-get install -y autoconf automake libtool pkg-config build-essential
  autoreconf -i
  chmod +x configure
  ./configure
  else
  echo "No Autotools entrypoint found (configure, autogen.sh, or configure.ac)." >&2
  echo "Repository root listing:";
  ls -la
  exit 1
  fi

2. Ensure the subsequent make / make check / make distcheck steps remain and execute in the repository root (no change required unless the project uses an out-of-tree build; this patch assumes in-tree build).

3. Commit message: "ci: make C/C++ workflow generate configure via Autotools when needed"
   Pull request title: "ci: ensure Autotools configure is generated in C/C++ CI"
   Branch: fix/ci-autotools

Notes for reviewers:

• This change enforces Autotools usage. If the repository actually uses CMake or another build system, update the workflow accordingly.
• If the project requires extra libraries or dependencies for configure/make, add them to the install list in the step.
• The job ref shown in the failing run is: cd8c4b6; this PR modifies the workflow file at .github/workflows/c-cpp.yml referenced by that run.

Please create a branch from main, apply the change to .github/workflows/c-cpp.yml, and open a pull request with the description above.

This pull request was created as a result of the following prompt from Copilot chat.

The repository's C/C++ CI workflow currently runs ./configure directly but many branches do not include a pre-generated configure script, causing the job to fail with: "./configure: No such file or directory" (see job 54655044154 logs). The workflow file that ran is .github/workflows/c-cpp.yml (ref: cd8c4b6).

Goal: Update the workflow to reliably build Autotools-based projects by generating configure when needed (autoreconf/autogen.sh) and installing required tools. Keep existing make / make check / make distcheck steps.

Required changes to implement in a new branch (suggested branch name: fix/ci-autotools):

1. Update .github/workflows/c-cpp.yml to replace the existing configure step (which runs "./configure") with a Prepare build (Autotools) step that:
   • Detects whether configure exists and runs it if present.
   • If autogen.sh exists, runs it.
   • If configure.ac or configure.in exists, installs necessary packages and runs autoreconf -i, then runs ./configure.
   • Prints the repository root listing and fails with a helpful message if no supported Autotools entrypoint is found.

Use the following shell snippet for the step content (preserve set -e so the job fails on error):

• name: Prepare build (Autotools)
  run: |
  set -e
  if [ -f configure ]; then
  echo "Running ./configure"
  chmod +x configure
  ./configure
  elif [ -f autogen.sh ]; then
  echo "Running ./autogen.sh"
  chmod +x autogen.sh
  ./autogen.sh
  elif [ -f configure.ac ] || [ -f configure.in ]; then
  echo "Running autoreconf -i"
  sudo apt-get update
  sudo apt-get install -y autoconf automake libtool pkg-config build-essential
  autoreconf -i
  chmod +x configure
  ./configure
  else
  echo "No Autotools entrypoint found (configure, autogen.sh, or configure.ac)." >&2
  echo "Repository root listing:";
  ls -la
  exit 1
  fi

2. Ensure the subsequent make / make check / make distcheck steps remain and execute in the repository root (no change required unless the project uses an out-of-tree build; this patch assumes in-tree build).

3. Commit message: "ci: make C/C++ workflow generate configure via Autotools when needed"
   Pull request title: "ci: ensure Autotools configure is generated in C/C++ CI"
   Branch: fix/ci-autotools

Notes for reviewers:

• This change enforces Autotools usage. If the repository actually uses CMake or another build system, update the workflow accordingly.
• If the project requires extra libraries or dependencies for configure/make, add them to the install list in the step.
• The job ref shown in the failing run is: cd8c4b6; this PR modifies the workflow file at .github/workflows/c-cpp.yml referenced by that run.

Please create a branch from main, apply the change to .github/workflows/c-cpp.yml, and open a pull request with the description above.

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