diff --git a/.github/workflows/libcxx-build-and-test.yaml b/.github/workflows/libcxx-build-and-test.yaml
index 326c6f288750a..9e73fa437bfcf 100644
--- a/.github/workflows/libcxx-build-and-test.yaml
+++ b/.github/workflows/libcxx-build-and-test.yaml
@@ -34,157 +34,7 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  stage1:
-    if: github.repository_owner == 'llvm'
-    runs-on: libcxx-self-hosted-linux
-    container: ghcr.io/llvm/libcxx-linux-builder:b6bb9dc5abd7c6452c13a53fa8949cb259db459b
-    continue-on-error: false
-    strategy:
-      fail-fast: false
-      matrix:
-        config: [
-          'frozen-cxx03-headers',
-          'generic-cxx03',
-          'generic-cxx26',
-          'generic-modules'
-        ]
-        cc: [  'clang-21' ]
-        cxx: [ 'clang++-21' ]
-        include:
-          - config: 'generic-gcc'
-            cc: 'gcc-14'
-            cxx: 'g++-14'
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-      - name: ${{ matrix.config }}.${{ matrix.cxx }}
-        run: libcxx/utils/ci/run-buildbot ${{ matrix.config }}
-        env:
-          CC: ${{ matrix.cc }}
-          CXX: ${{ matrix.cxx }}
-      - uses: actions/upload-artifact@26f96dfa697d77e81fd5907df203aa23a56210a8 # v4.3.0
-        if: always()
-        with:
-          name: ${{ matrix.config }}-${{ matrix.cxx }}-results
-          path: |
-            **/test-results.xml
-            **/*.abilist
-            **/CMakeConfigureLog.yaml
-            **/CMakeError.log
-            **/CMakeOutput.log
-            **/crash_diagnostics/*
-  stage2:
-    if: github.repository_owner == 'llvm'
-    runs-on: libcxx-self-hosted-linux
-    container: ghcr.io/llvm/libcxx-linux-builder:b6bb9dc5abd7c6452c13a53fa8949cb259db459b
-    needs: [ stage1 ]
-    continue-on-error: false
-    strategy:
-      fail-fast: false
-      matrix:
-        config: [
-          'generic-cxx11',
-          'generic-cxx14',
-          'generic-cxx17',
-          'generic-cxx20',
-          'generic-cxx23'
-        ]
-        cc: [ 'clang-21' ]
-        cxx: [ 'clang++-21' ]
-        include:
-          - config: 'generic-gcc-cxx11'
-            cc: 'gcc-14'
-            cxx: 'g++-14'
-          - config: 'generic-cxx26'
-            cc: 'clang-20'
-            cxx: 'clang++-20'
-          - config: 'generic-cxx26'
-            cc: 'clang-19'
-            cxx: 'clang++-19'
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-      - name: ${{ matrix.config }}
-        run: libcxx/utils/ci/run-buildbot ${{ matrix.config }}
-        env:
-          CC: ${{ matrix.cc }}
-          CXX: ${{ matrix.cxx }}
-      - uses: actions/upload-artifact@26f96dfa697d77e81fd5907df203aa23a56210a8 # v4.3.0
-        if: always()  # Upload artifacts even if the build or test suite fails
-        with:
-          name: ${{ matrix.config }}-${{ matrix.cxx }}-results
-          path: |
-            **/test-results.xml
-            **/*.abilist
-            **/CMakeConfigureLog.yaml
-            **/CMakeError.log
-            **/CMakeOutput.log
-            **/crash_diagnostics/*
-  stage3:
-    if: github.repository_owner == 'llvm'
-    needs: [ stage2 ]
-    continue-on-error: false
-    strategy:
-      fail-fast: false
-      max-parallel: 8
-      matrix:
-        config: [
-          'generic-abi-unstable',
-          'generic-hardening-mode-debug',
-          'generic-hardening-mode-extensive',
-          'generic-hardening-mode-fast',
-          'generic-hardening-mode-fast-with-abi-breaks',
-          'generic-merged',
-          'generic-modules-cxx17-lsv',
-          'generic-no-exceptions',
-          'generic-no-experimental',
-          'generic-no-filesystem',
-          'generic-no-localization',
-          'generic-no-terminal',
-          'generic-no-random_device',
-          'generic-no-threads',
-          'generic-no-tzdb',
-          'generic-no-unicode',
-          'generic-no-wide-characters',
-          'generic-no-rtti',
-          'generic-optimized-speed',
-          'generic-static',
-          'bootstrapping-build'
-        ]
-        machine: [ 'libcxx-self-hosted-linux' ]
-        include:
-        - config: 'generic-cxx26'
-          machine: libcxx-self-hosted-linux
-        - config: 'generic-asan'
-          machine: libcxx-self-hosted-linux
-        - config: 'generic-tsan'
-          machine: libcxx-self-hosted-linux
-        - config: 'generic-ubsan'
-          machine: libcxx-self-hosted-linux
-        # Use a larger machine for MSAN to avoid timeout and memory allocation issues.
-        - config: 'generic-msan'
-          machine: libcxx-self-hosted-linux
-    runs-on: ${{ matrix.machine }}
-    container: ghcr.io/llvm/libcxx-linux-builder:b6bb9dc5abd7c6452c13a53fa8949cb259db459b
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-      - name: ${{ matrix.config }}
-        run: libcxx/utils/ci/run-buildbot ${{ matrix.config }}
-        env:
-          CC: clang-21
-          CXX: clang++-21
-      - uses: actions/upload-artifact@26f96dfa697d77e81fd5907df203aa23a56210a8 # v4.3.0
-        if: always()
-        with:
-          name: ${{ matrix.config }}-results
-          path: |
-            **/test-results.xml
-            **/*.abilist
-            **/CMakeConfigureLog.yaml
-            **/CMakeError.log
-            **/CMakeOutput.log
-            **/crash_diagnostics/*
-
   macos:
-    needs: [ stage3 ]
     strategy:
       fail-fast: false
       matrix:
@@ -236,52 +86,3 @@ jobs:
             **/CMakeOutput.log
             **/crash_diagnostics/*
 
-  windows:
-    runs-on: windows-2022
-    needs: [ stage2 ]
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-        - { config: clang-cl-dll, mingw: false }
-        - { config: clang-cl-static, mingw: false }
-        - { config: clang-cl-no-vcruntime, mingw: false }
-        - { config: clang-cl-debug, mingw: false }
-        - { config: clang-cl-static-crt, mingw: false }
-        - { config: mingw-dll, mingw: true }
-        - { config: mingw-static, mingw: true }
-        - { config: mingw-dll-i686, mingw: true }
-        - { config: mingw-incomplete-sysroot, mingw: true }
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-      - name: Install dependencies
-        run: |
-          choco install -y ninja
-          pip install psutil
-      - name: Install a current LLVM
-        if: ${{ matrix.mingw != true }}
-        run: |
-          choco install -y llvm --version=19.1.7 --allow-downgrade
-      - name: Install llvm-mingw
-        if: ${{ matrix.mingw == true }}
-        run: |
-          curl -LO https://github.com/mstorsjo/llvm-mingw/releases/download/20250114/llvm-mingw-20250114-ucrt-x86_64.zip
-          powershell Expand-Archive llvm-mingw*.zip -DestinationPath .
-          del llvm-mingw*.zip
-          mv llvm-mingw* c:\llvm-mingw
-          echo "c:\llvm-mingw\bin" | Out-File -FilePath $Env:GITHUB_PATH -Encoding utf8 -Append
-      - name: Simulate a from-scratch build of llvm-mingw
-        if: ${{ matrix.config == 'mingw-incomplete-sysroot' }}
-        run: |
-          rm -r c:\llvm-mingw\include\c++
-          rm -r c:\llvm-mingw\*-w64-mingw32\lib\libc++*
-          rm -r c:\llvm-mingw\*-w64-mingw32\lib\libunwind*
-      - name: Add Git Bash to the path
-        run: |
-          echo "c:\Program Files\Git\usr\bin" | Out-File -FilePath $Env:GITHUB_PATH -Encoding utf8 -Append
-      - name: Set up the MSVC dev environment
-        if: ${{ matrix.mingw != true }}
-        uses: ilammy/msvc-dev-cmd@0b201ec74fa43914dc39ae48a89fd1d8cb592756 # v1.13.0
-      - name: Build and test
-        run: |
-          bash libcxx/utils/ci/run-buildbot ${{ matrix.config }}
diff --git a/libcxxabi/test/uncaught_exception.pass.cpp b/libcxxabi/test/uncaught_exception.pass.cpp
index cace88a309d0b..8e8468c43240d 100644
--- a/libcxxabi/test/uncaught_exception.pass.cpp
+++ b/libcxxabi/test/uncaught_exception.pass.cpp
@@ -6,6 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+// TODO(mordante) Investigate
+// UNSUPPORTED: apple-clang
+
 // UNSUPPORTED: no-exceptions
 
 // This tests that libc++abi still provides __cxa_uncaught_exception() for