ci: mcpp 0.0.68 + recover GL window/imgui-module smokes to blocking

mcpp 0.0.68 fixes the dimensional ABI bug (glibc C lib buildable under
clang/libc++), so the imgui-module smoke (pins llvm@20.1.7 → glfw) and the GL
window smoke move back from nightly into the blocking smoke-full-linux. Bump
MCPP_VERSION 0.0.67→0.0.68 (incl. portable archives). Verified locally on
0.0.68: imgui-module-smoke runs (Dear ImGui 1.92.8 module package ok).
Correct the plan doc §8.2 root cause (was mis-attributed).

Author: Sunrisepeak

.agents/docs/2026-06-27-add-cjson-and-nlohmann-json-plan.md

@@ -317,13 +317,17 @@ PR #48。两处与「升级到最新 mcpp 0.0.67」相关的 CI 排查:
    门控(默认不链)→ 无 main;0.0.46 **忽略** feature 总是链入,故旧版「假绿」。
    **修复**:依赖声明改 `gtest = { version = "1.15.2", features = ["main"] }`(本地 0.0.66 实测全绿)。
 
-2. **glfw ABI mismatch(mcpp 0.0.67 回归,已隔离,待 mcpp 侧排查)**:`smoke_compat_imgui_window.sh`
-   在 0.0.67 CI 报 `ABI mismatch: compat.glfw requires abi=glibc but resolved clang 20.1.7 (libc++)`,
-   **尽管工程已 `default = "gcc@16.1.0"`**。对照证据:同脚本 0.0.66 本地正常解析 gcc 并通过;glfw 在
-   0.0.67 别处(linux `smoke_compat_imgui.sh`、mac/windows portable)均正常构建。→ 判定为 **mcpp 0.0.67
-   工具链解析回归**(对带 abi 要求的 glfw 依赖错误回退 clang/libc++),非配方/非本 PR。
-   **处置**:把 GL 窗口 + imgui-module 两个 demo 移到 `smoke-gl-linux`(仅 nightly + 手动 dispatch),
-   不阻塞 PR/main;core/imgui/archive 仍在 0.0.67 阻塞跑。**待 mcpp 侧单独修工具链解析后回收。**
+2. **glfw `abi:glibc` 在 clang/libc++ 下误报(mcpp core bug,已在 0.0.68 修复并回收)**:
+   CI 报 `ABI mismatch: compat.glfw requires abi=glibc but resolved clang 20.1.7 (libc++)`。
+   **真正肇事**是 `smoke_imgui_module.sh`(**显式 pin `llvm@20.1.7`**,非 imgui_window、非"工具链误解析")——
+   其传递依赖 glfw 声明 `abi:glibc`。**根因**:mcpp `prepare.cppm` 的 `abi:` 门控把 **libc ABI** 与
+   **C++ 标准库**混为一谈(`stdlibId=="libc++"` 抢占了 glibc),而 clang+libc++ 的三元组是 `*-linux-gnu`,
+   libc 仍是 glibc → 把 glibc 的 C 库误判不兼容。检查随 0.0.54 引入,故 CI 旧 pin 0.0.46 不报、0.0.67 报。
+   **修复**:mcpp **0.0.68**(#178)把 ABI 建成维度模型(libc / cxxstdlib 等正交,未声明即 don't-care);
+   分析+设计见 mcpp 仓 `.agents/docs/2026-06-27-glfw-abi-glibc-vs-libcxx-conflation-analysis.md`、
+   `2026-06-27-abi-compat-model-single-pr-design.md`。
+   **回收**:本 PR 把 CI 升到 `0.0.68` 并将 GL window + imgui-module 两 smoke 从 nightly 移回阻塞 `smoke-full-linux`
+   (本地 0.0.68 实测 `imgui-module-smoke` 在 llvm 下 `Dear ImGui 1.92.8 module package ok`)。
 
 ### 8.3 CI 选跑实测(PR #48)
 detect 正确产出 `examples=["cjson","nlohmann.json"]`;`smoke-examples (cjson)`/`(nlohmann.json)`

.github/workflows/validate.yml

@@ -11,7 +11,7 @@ on:
   workflow_dispatch:
 
 env:
-  MCPP_VERSION: "0.0.67"
+  MCPP_VERSION: "0.0.68"
 
 jobs:
   lint:
@@ -216,47 +216,13 @@ jobs:
           timeout 1800 bash tests/smoke_compat_core.sh
           timeout 1800 bash tests/smoke_compat_imgui.sh
           timeout 1800 bash tests/smoke_compat_archive.sh
-
-  # ── GLFW/OpenGL window + imgui-module demos (nightly / manual only) ────
-  # These two depend on `compat.glfw` (abi=glibc) and the GLX/OpenGL runtime.
-  # On mcpp 0.0.67 the window demo intermittently resolves a clang/libc++
-  # toolchain for compat.glfw despite a `default = "gcc@16.1.0"` pin, failing
-  # with `ABI mismatch: compat.glfw requires abi=glibc`. The same scripts pass
-  # on 0.0.66 locally, and glfw builds fine on 0.0.67 elsewhere (linux imgui
-  # smoke + mac/windows portable), so this is an mcpp toolchain-resolution
-  # regression unrelated to package descriptors — tracked separately. Kept out
-  # of the PR-blocking path (display/driver/ABI-sensitive, already optional)
-  # but still exercised on the nightly schedule and on manual dispatch.
-  smoke-gl-linux:
-    if: github.event_name == 'schedule' || github.event_name == 'workflow_dispatch'
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Restore mcpp registry cache
-        uses: actions/cache@v4
-        with:
-          path: ~/.mcpp/registry
-          key: mcpp-registry-${{ runner.os }}-${{ env.MCPP_VERSION }}-${{ hashFiles('pkgs/**/*.lua', 'tests/**', '.github/workflows/validate.yml') }}
-          restore-keys: |
-            mcpp-registry-${{ runner.os }}-${{ env.MCPP_VERSION }}-
-      - name: Download mcpp
-        run: |
-          curl -L -fsS -o mcpp.tar.gz \
-            "https://github.com/mcpp-community/mcpp/releases/download/v${MCPP_VERSION}/mcpp-${MCPP_VERSION}-linux-x86_64.tar.gz"
-          tar -xzf mcpp.tar.gz
-          root="$PWD/mcpp-${MCPP_VERSION}-linux-x86_64"
-          mkdir -p "$HOME/.mcpp/registry"
-          cp -a "$root/registry/." "$HOME/.mcpp/registry/"
-          echo "MCPP=$root/bin/mcpp" >> "$GITHUB_ENV"
-          echo "MCPP_VENDORED_XLINGS=$root/registry/bin/xlings" >> "$GITHUB_ENV"
-          echo "$root/bin" >> "$GITHUB_PATH"
-      - name: Run GL window + imgui-module smoke tests
-        env:
-          MCPP_INDEX_SMOKE_MCPP_HOME: ${{ runner.temp }}/mcpp-smoke-home
-          MCPP_INDEX_SMOKE_CACHE_DIR: ${{ runner.temp }}/mcpp-smoke-cache
-        run: |
-          mkdir -p "$MCPP_INDEX_SMOKE_MCPP_HOME"
-          "$MCPP" --version
+          # GLFW/OpenGL window + imgui-module demos. These pull compat.glfw
+          # (abi:glibc). The imgui-module smoke pins llvm@20.1.7 (clang/libc++);
+          # on mcpp ≤0.0.67 that tripped the conflated `abi:` gate ("requires
+          # abi=glibc … is abi=libc++") because a clang+libc++ toolchain on
+          # *-linux-gnu was mislabelled. Fixed in mcpp 0.0.68 (dimensional ABI
+          # model: libc and cxxstdlib are independent axes), so these are back in
+          # the blocking set. The window run itself stays opt-in (needs a display).
           timeout 1800 bash tests/smoke_compat_imgui_window.sh
           timeout 1800 bash tests/smoke_imgui_module.sh
 
@@ -272,14 +238,14 @@ jobs:
         include:
           - platform: macos
             os: macos-15
-            archive: mcpp-0.0.67-macosx-arm64.tar.gz
-            root: mcpp-0.0.67-macosx-arm64
+            archive: mcpp-0.0.68-macosx-arm64.tar.gz
+            root: mcpp-0.0.68-macosx-arm64
             mcpp: bin/mcpp
             xlings: registry/bin/xlings
           - platform: windows
             os: windows-latest
-            archive: mcpp-0.0.67-windows-x86_64.zip
-            root: mcpp-0.0.67-windows-x86_64
+            archive: mcpp-0.0.68-windows-x86_64.zip
+            root: mcpp-0.0.68-windows-x86_64
             mcpp: bin/mcpp.exe
             xlings: registry/bin/xlings.exe
     steps: