Discuss testing strategy for third-party dependency versions

In the otel-cpp SIG meeting today we discussed possible changes to what versions of third-party dependencies are tested in CI.

The goal is to test different versions of third-party dependencies in CI to catch breaking changes early and to better communicate the range of third-party versions that are supported by a opentelemetry-cpp release.

Current Strategy

• The main CI workflow tests the versions defined by the git tags in opentelemetry-cpp/third_party_release
• The cmake_install.yml workflow tests versions defined by:
  • CMake installed packages from git tags in:
    • install/cmake/third_party_minimum - intended to cover the oldest supported release for each dependency
    • install/cmake/third_party_stable - intended to represent a stable release (running in production for a year or so) of each dependency
    • install/cmake/third_party_latest - intended to represent the latest release of each dependency
  • Conan installed versions of packages defined by
    • install/conan/conanfile_stable.txt - intended to represent a stable (within a year or so) versions available in conan-center-index
    • install/conan/conanfile_latest.txt - intended to be the latest versions available in conan-center-index
  • apt installed packages for all dependencies with Ubuntu 24.04
  • Homebrew installed packages (latest) for all dependencies with MacOS
  • vcpkg installed versions defined by the current vcpkg git submodule

Proposal discussed

• Change an existing third-party tag file or add a new one to cover the latest versions of dependencies that support C++14 and those that support C++17.

Please add feedback/ideas/concerns on the approaches in this issue thread. To be discussed in future SIG meetings.

Review the existing CI workflows and version sources named in the issue, including .github/workflows/cmake_install.yml, third_party_release, the install/cmake files, and the Conan files. Compare the current dependency coverage with the proposed C++14 and C++17 strategy; the work is complete when the SIG agrees on an approach and the corresponding version-testing changes are defined.