🧹 Nitpick | 🔵 Trivial | 🏗️ Heavy lift

Consider validating find_package(slang) after install, not just that cmake --install succeeds.

Issue #11359 manifested as find_package(slang) failing because slangTargets.cmake wasn't installed — yet the install command itself still succeeded with the old guard in place. The "not in any export set" failure is caught at configure/generate time now, but this step alone would not catch a future regression where the install completes but the exported package config is inconsistent. A minimal consumer find_package(slang CONFIG PATHS install ... NO_DEFAULT_PATH) check (resolving slang::slang) would directly guard the originally-reported breakage.

🟡 Gap: pkgconfig file installed for STATIC builds, but .pc template explicitly does not support static linking

Removing the STATIC guard makes install(FILES "${PROJECT_BINARY_DIR}/slang-compiler.pc" DESTINATION "lib/pkgconfig") fire for UNIX static builds too. extras/pkgconfig/slang-compiler.pc.in is not equipped for that case:

Libs: -L${libdir} -lslang-compiler
Cflags: -I${includedir}

# Note: pkg-config --static is not currently supported,
# so Libs.private is not populated.

Libs: names only -lslang-compiler and Libs.private is empty. After a STATIC install, pkg-config --libs slang-compiler returns an incomplete link line that omits every transitive internal archive (core, compiler-core, slang-capability-*, slang-lookup-tables, plus bundled vendored libs like miniz/lz4 — see docs/building.md listing the static dependency chain). pkg-config users following the manifest will hit unresolved-symbol errors at link time.

Example: a downstream UNIX project does pkg-config --libs slang-compiler after cmake --install of a SLANG_LIB_TYPE=STATIC Slang. They get -L<prefix>/lib -lslang-compiler and ld reports unresolved references into core::* and compiler-core::*. Before this PR, no .pc was installed so the project would fall back to find_package(slang) (which is the well-supported path with this PR).

Suggested fix: either keep the pkgconfig install gated on shared (the simplest patch and consistent with the .pc.in comment), or populate Libs.private with the full static dependency chain when SLANG_LIB_TYPE is STATIC and document that pkg-config --static --libs slang-compiler is required.

if(UNIX AND NOT ${SLANG_LIB_TYPE} STREQUAL "STATIC")
    configure_file(...)
    install(FILES "${PROJECT_BINARY_DIR}/slang-compiler.pc" DESTINATION "lib/pkgconfig")
endif()

🟡 Gap: cmake --install doesn't exercise the consumer-side regression of #11359

The reported failure mode in #11359 is find_package(slang) blowing up on a static install because slangConfig.cmake always include()s a slangTargets.cmake that wasn't installed. The new step only runs cmake --install build --config "$cmake_config" --prefix install. That covers the case where install(EXPORT SlangTargets ...) itself errors at install time, but it doesn't exercise the actual user path that broke.

In particular, if a future change re-introduces a guard around just the install(EXPORT ...) call (the exact shape of the original bug), cmake --install still succeeds — it just silently doesn't ship slangTargets.cmake. The regression resurfaces only when a downstream calls find_package(slang), which CI never does.

Suggested fix: chain a tiny find_package smoke test after the install step. The slang_DIR path differs by OS because SLANG_CMAKE_CONFIG_DIR is cmake on Windows and ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME} elsewhere (CMakeLists.txt around line 652).

- name: Smoke-test find_package(slang) against install prefix
  if: matrix.install_test == 'true' && (matrix.linux_only != 'true' || inputs.os == 'linux') && (matrix.windows_only != 'true' || inputs.os == 'windows') && matrix.container_only != 'true' && (matrix.skip_linux_aarch64 != 'true' || inputs.os != 'linux' || inputs.platform != 'aarch64')
  shell: bash
  run: |
    mkdir -p find_pkg_test && cd find_pkg_test
    cat > CMakeLists.txt <<'EOF'
    cmake_minimum_required(VERSION 3.22)
    project(find_slang_smoke LANGUAGES CXX)
    find_package(slang CONFIG REQUIRED)
    if(NOT TARGET slang::slang)
      message(FATAL_ERROR "slang::slang target missing after find_package")
    endif()
    EOF
    cmake -S . -B build -Dslang_ROOT="$GITHUB_WORKSPACE/install"

Same change applies to .github/workflows/cmake-options-build-container.yml.