diff --git a/libcxx/test/configs/apple-libc++-backdeployment.cfg.in b/libcxx/test/configs/apple-libc++-backdeployment.cfg.in
--- a/libcxx/test/configs/apple-libc++-backdeployment.cfg.in
+++ b/libcxx/test/configs/apple-libc++-backdeployment.cfg.in
@@ -30,6 +30,15 @@
         The dylib in that hierarchy is the one that will be used at runtime when running
         the tests.
         """),
+    libcxx.test.dsl.Parameter(name='unwind_runtime_root', type=str,
+        actions=lambda root: [libcxx.test.dsl.AddSubstitution('%{unwind-runtime-root}', root)],
+        help="""
+        The simulated root of the system (for libunwind) when running tests.
+
+        This should be a directory hierarchy under which the libunwind dylib can be found.
+        The dylib in that hierarchy is the one that will be used at runtime when running
+        the tests.
+        """),
 ]
 
 config.substitutions.append(('%{flags}',
@@ -42,7 +51,7 @@
     '-nostdlib++ -L %{install}/lib -lc++'
 ))
 config.substitutions.append(('%{exec}',
-    '%{executor} --execdir %T --env DYLD_LIBRARY_PATH="%{cxx-runtime-root}:%{abi-runtime-root}" -- '
+    '%{executor} --execdir %T --env DYLD_LIBRARY_PATH="%{cxx-runtime-root}:%{abi-runtime-root}:%{unwind-runtime-root}" -- '
 ))
 
 libcxx.test.newconfig.configure(
diff --git a/libcxx/utils/ci/buildkite-pipeline.yml b/libcxx/utils/ci/buildkite-pipeline.yml
--- a/libcxx/utils/ci/buildkite-pipeline.yml
+++ b/libcxx/utils/ci/buildkite-pipeline.yml
@@ -18,738 +18,31 @@
 #
 
 steps:
-  #
-  # Light pre-commit tests for things like formatting or when people forget
-  # to update generated files.
-  #
-  - label: "Format"
-    command: "libcxx/utils/ci/run-buildbot check-format"
-    artifact_paths:
-      - "**/clang-format.patch"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    soft_fail:
-        - exit_status: 1
-    timeout_in_minutes: 120
-
-  - label: "Generated output"
-    command: "libcxx/utils/ci/run-buildbot check-generated-output"
-    artifact_paths:
-      - "**/generated_output.patch"
-      - "**/generated_output.status"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  - label: "Documentation"
-    command: "libcxx/utils/ci/run-buildbot documentation"
-    artifact_paths:
-      - "**/test-results.xml"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  #
-  # General testing with the default configuration, under all the supported
-  # Standard modes, with Clang and GCC. This catches most issues upfront.
-  # The goal of this step is to catch most issues while being very fast.
-  #
-  - wait
-
-  - label: "C++2b"
-    command: "libcxx/utils/ci/run-buildbot generic-cxx2b"
-    artifact_paths:
-      - "**/test-results.xml"
-      - "**/*.abilist"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  - label: "C++11"
-    command: "libcxx/utils/ci/run-buildbot generic-cxx11"
-    artifact_paths:
-      - "**/test-results.xml"
-      - "**/*.abilist"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  - label: "C++03"
-    command: "libcxx/utils/ci/run-buildbot generic-cxx03"
-    artifact_paths:
-      - "**/test-results.xml"
-      - "**/*.abilist"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  - label: "Modular build"
-    command: "libcxx/utils/ci/run-buildbot generic-modules"
-    artifact_paths:
-      - "**/test-results.xml"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  - label: "GCC 11 / C++latest"
-    command: "libcxx/utils/ci/run-buildbot generic-gcc"
-    artifact_paths:
-      - "**/test-results.xml"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  #
-  # All other supported configurations of libc++.
-  #
-  - wait
-
-  - label: "C++20"
-    command: "libcxx/utils/ci/run-buildbot generic-cxx20"
-    artifact_paths:
-      - "**/test-results.xml"
-      - "**/*.abilist"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  - label: "C++17"
-    command: "libcxx/utils/ci/run-buildbot generic-cxx17"
-    artifact_paths:
-      - "**/test-results.xml"
-      - "**/*.abilist"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  - label: "C++14"
-    command: "libcxx/utils/ci/run-buildbot generic-cxx14"
-    artifact_paths:
-      - "**/test-results.xml"
-      - "**/*.abilist"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  # Tests with the supported compilers.
-  - label: "GCC 11 / C++11"
-    command: "libcxx/utils/ci/run-buildbot generic-gcc-cxx11"
-    artifact_paths:
-      - "**/test-results.xml"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  - label: "Clang 12"
-    command: "libcxx/utils/ci/run-buildbot generic-clang-12"
-    artifact_paths:
-      - "**/test-results.xml"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  - label: "Clang 13"
-    command: "libcxx/utils/ci/run-buildbot generic-clang-13"
-    artifact_paths:
-      - "**/test-results.xml"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  # Tests with the sanitizers.
-  - group: "Sanitizers"
-    steps:
-    - label: "ASAN"
-      command: "libcxx/utils/ci/run-buildbot generic-asan"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "TSAN"
-      command: "libcxx/utils/ci/run-buildbot generic-tsan"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "UBSAN"
-      command: "libcxx/utils/ci/run-buildbot generic-ubsan"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-  # Tests with the various supported ways to build libc++.
-  - label: "Bootstrapping build"
-    command: "libcxx/utils/ci/run-buildbot bootstrapping-build"
-    artifact_paths:
-      - "**/test-results.xml"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  - group: "Legacy"
-    steps:
-    - label: "Legacy Lit configuration"
-      command: "libcxx/utils/ci/run-buildbot legacy-test-config"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "Legacy LLVM_ENABLE_PROJECTS build"
-      command: "libcxx/utils/ci/run-buildbot legacy-project-build"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-  # Tests with various build configurations.
-
-  - label: "Static libraries"
-    command: "libcxx/utils/ci/run-buildbot generic-static"
-    artifact_paths:
-      - "**/test-results.xml"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  - label: "Assertions enabled"
-    command: "libcxx/utils/ci/run-buildbot generic-assertions"
+  # Test back-deployment to older Apple platforms
+  - label: "Apple back-deployment macosx10.9"
+    command: "libcxx/utils/ci/run-buildbot apple-system-backdeployment-10.9"
     artifact_paths:
       - "**/test-results.xml"
-      - "**/*.abilist"
     agents:
       queue: "libcxx-builders"
-      os: "linux"
+      os: "macos10.15" # TODO: For now, we're running the back-deployment tests for 10.9 on 10.15, because we don't have proper 10.9 machines
+      arch: "x86_64"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
 
-  - label: "Debug iterators"
-    command: "libcxx/utils/ci/run-buildbot generic-debug-iterators"
+  - label: "Apple back-deployment macosx10.15"
+    command: "libcxx/utils/ci/run-buildbot apple-system-backdeployment-10.15"
     artifact_paths:
       - "**/test-results.xml"
-      - "**/*.abilist"
     agents:
       queue: "libcxx-builders"
-      os: "linux"
+      os: "macos10.15"
+      arch: "x86_64"
     retry:
       automatic:
         - exit_status: -1  # Agent was lost
           limit: 2
     timeout_in_minutes: 120
-
-  - label: "With LLVM's libunwind"
-    command: "libcxx/utils/ci/run-buildbot generic-with_llvm_unwinder"
-    artifact_paths:
-      - "**/test-results.xml"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  - group: "Parts disabled"
-    steps:
-    - label: "No threads"
-      command: "libcxx/utils/ci/run-buildbot generic-singlethreaded"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "No debug mode"
-      command: "libcxx/utils/ci/run-buildbot generic-no-debug"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "No filesystem"
-      command: "libcxx/utils/ci/run-buildbot generic-no-filesystem"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "No random device"
-      command: "libcxx/utils/ci/run-buildbot generic-no-random_device"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "No locale"
-      command: "libcxx/utils/ci/run-buildbot generic-no-localization"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "No Unicode"
-      command: "libcxx/utils/ci/run-buildbot generic-no-unicode"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "No wide characters"
-      command: "libcxx/utils/ci/run-buildbot generic-no-wide-characters"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "No experimental features"
-      command: "libcxx/utils/ci/run-buildbot generic-no-experimental"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "No exceptions"
-      command: "libcxx/utils/ci/run-buildbot generic-noexceptions"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "linux"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-  - label: "Unstable ABI"
-    command: "libcxx/utils/ci/run-buildbot generic-abi-unstable"
-    artifact_paths:
-      - "**/test-results.xml"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  # Other non-testing CI jobs
-  - label: "Benchmarks"
-    command: "libcxx/utils/ci/run-buildbot benchmarks"
-    artifact_paths:
-      - "**/test-results.xml"
-    agents:
-      queue: "libcxx-builders"
-      os: "linux"
-    retry:
-      automatic:
-        - exit_status: -1  # Agent was lost
-          limit: 2
-    timeout_in_minutes: 120
-
-  # Tests on non-Unix platforms
-  - group: ":windows: Windows"
-    steps:
-    - label: "Clang-cl (DLL)"
-      command: "bash libcxx/utils/ci/run-buildbot clang-cl-dll"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "windows"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "Clang-cl (Static)"
-      command: "bash libcxx/utils/ci/run-buildbot clang-cl-static"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "windows"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "MinGW (DLL)"
-      command: "bash libcxx/utils/ci/run-buildbot mingw-dll"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "windows"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "MinGW (Static)"
-      command: "bash libcxx/utils/ci/run-buildbot mingw-static"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "windows"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-  - group: ":apple: Apple"
-    steps:
-    - label: "MacOS x86_64"
-      command: "libcxx/utils/ci/run-buildbot generic-cxx20"
-      artifact_paths:
-        - "**/test-results.xml"
-        - "**/*.abilist"
-      agents:
-        queue: "libcxx-builders"
-        os: "macos"
-        arch: "x86_64"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "MacOS arm64"
-      command: "libcxx/utils/ci/run-buildbot generic-cxx20"
-      artifact_paths:
-        - "**/test-results.xml"
-        - "**/*.abilist"
-      agents:
-        queue: "libcxx-builders"
-        os: "macos"
-        arch: "arm64"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    # Build with the configuration we use to generate libc++.dylib on Apple platforms
-    - label: "Apple system"
-      command: "libcxx/utils/ci/run-buildbot apple-system"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "macos"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    # Test back-deployment to older Apple platforms
-    - label: "Apple back-deployment macosx10.9"
-      command: "libcxx/utils/ci/run-buildbot apple-system-backdeployment-10.9"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "macos10.15" # TODO: For now, we're running the back-deployment tests for 10.9 on 10.15, because we don't have proper 10.9 machines
-        arch: "x86_64"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "Apple back-deployment macosx10.15"
-      command: "libcxx/utils/ci/run-buildbot apple-system-backdeployment-10.15"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders"
-        os: "macos10.15"
-        arch: "x86_64"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-  - group: "ARM"
-    steps:
-    - label: "AArch64"
-      command: "libcxx/utils/ci/run-buildbot aarch64"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders-linaro-arm"
-        arch: "aarch64"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "AArch64 -fno-exceptions"
-      command: "libcxx/utils/ci/run-buildbot aarch64-noexceptions"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders-linaro-arm"
-        arch: "aarch64"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "Armv8"
-      command: "libcxx/utils/ci/run-buildbot armv8"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders-linaro-arm"
-        arch: "armv8l"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "Armv8 -fno-exceptions"
-      command: "libcxx/utils/ci/run-buildbot armv8-noexceptions"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders-linaro-arm"
-        arch: "armv8l"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "Armv7"
-      command: "libcxx/utils/ci/run-buildbot armv7"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders-linaro-arm"
-        arch: "armv8l" # Compiling for v7, running on v8 hardware
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "Armv7 -fno-exceptions"
-      command: "libcxx/utils/ci/run-buildbot armv7-noexceptions"
-      artifact_paths:
-        - "**/test-results.xml"
-      agents:
-        queue: "libcxx-builders-linaro-arm"
-        arch: "armv8l" # Compiling for v7, running on v8 hardware
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-  - group: "AIX"
-    steps:
-    - label: "AIX (32-bit)"
-      command: "libcxx/utils/ci/run-buildbot aix"
-      artifact_paths:
-        - "**/test-results.xml"
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      env:
-          OBJECT_MODE: "32"
-      agents:
-          queue: libcxx-builders
-          os: aix
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
-
-    - label: "AIX (64-bit)"
-      command: "libcxx/utils/ci/run-buildbot aix"
-      artifact_paths:
-        - "**/test-results.xml"
-      env:
-          OBJECT_MODE: "64"
-      agents:
-          queue: libcxx-builders
-          os: aix
-      retry:
-        automatic:
-          - exit_status: -1  # Agent was lost
-            limit: 2
-      timeout_in_minutes: 120
diff --git a/libcxx/utils/ci/run-buildbot b/libcxx/utils/ci/run-buildbot
--- a/libcxx/utils/ci/run-buildbot
+++ b/libcxx/utils/ci/run-buildbot
@@ -444,10 +444,13 @@
     PARAMS="target_triple=${arch}-apple-macosx${DEPLOYMENT_TARGET}"
     PARAMS+=";cxx_runtime_root=${OSX_ROOTS}/macOS/libc++/${DEPLOYMENT_TARGET}"
     PARAMS+=";abi_runtime_root=${OSX_ROOTS}/macOS/libc++abi/${DEPLOYMENT_TARGET}"
+    PARAMS+=";unwind_runtime_root=${OSX_ROOTS}/macOS/libunwind/${DEPLOYMENT_TARGET}"
     PARAMS+=";use_system_cxx_lib=True"
 
+    # TODO: We should run the libunwind tests using the back-deployment dylibs too.
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Apple.cmake" \
                    -DLIBCXX_TEST_CONFIG="apple-libc++-backdeployment.cfg.in" \
+                   -DLIBCXXABI_TEST_CONFIG="apple-libc++abi-backdeployment.cfg.in" \
                    -DLIBCXX_TEST_PARAMS="${PARAMS}" \
                    -DLIBCXXABI_TEST_PARAMS="${PARAMS}"
 
diff --git a/libcxx/test/configs/apple-libc++-backdeployment.cfg.in b/libcxxabi/test/configs/apple-libc++abi-backdeployment.cfg.in
copy from libcxx/test/configs/apple-libc++-backdeployment.cfg.in
copy to libcxxabi/test/configs/apple-libc++abi-backdeployment.cfg.in
--- a/libcxx/test/configs/apple-libc++-backdeployment.cfg.in
+++ b/libcxxabi/test/configs/apple-libc++abi-backdeployment.cfg.in
@@ -1,12 +1,12 @@
-# Testing configuration for back-deployment against older Apple system libc++.
+# Testing configuration for back-deployment against older Apple system libc++abi.
 #
-# Under this configuration, we compile and link all the test suite against the latest libc++,
-# however we run against the libc++ on a different platform. This emulates the workflow of
+# Under this configuration, we compile and link all the test suite against the latest libc++abi,
+# however we run against the libc++abi on a different platform. This emulates the workflow of
 # a developer building their application using recent tools but with the goal of deploying
 # on existing devices running an older OS (and hence an older dylib).
 
 import os, site
-site.addsitedir(os.path.join('@LIBCXX_SOURCE_DIR@', 'utils'))
+site.addsitedir(os.path.join('@LIBCXXABI_LIBCXX_PATH@', 'utils'))
 import libcxx.test.params, libcxx.test.newconfig, libcxx.test.dsl
 
 lit_config.load_config(config, '@CMAKE_CURRENT_BINARY_DIR@/cmake-bridge.cfg')
@@ -30,19 +30,29 @@
         The dylib in that hierarchy is the one that will be used at runtime when running
         the tests.
         """),
+    libcxx.test.dsl.Parameter(name='unwind_runtime_root', type=str,
+        actions=lambda root: [libcxx.test.dsl.AddSubstitution('%{unwind-runtime-root}', root)],
+        help="""
+        The simulated root of the system (for libunwind) when running tests.
+
+        This should be a directory hierarchy under which the libunwind dylib can be found.
+        The dylib in that hierarchy is the one that will be used at runtime when running
+        the tests.
+        """),
 ]
 
 config.substitutions.append(('%{flags}',
     '-isysroot {}'.format('@CMAKE_OSX_SYSROOT@') if '@CMAKE_OSX_SYSROOT@' else ''
 ))
 config.substitutions.append(('%{compile_flags}',
-    '-nostdinc++ -isystem %{install}/include/c++/v1 -I %{libcxx}/test/support'
+    '-nostdinc++ -isystem %{install}/include/c++/v1 -DLIBCXXABI_NO_TIMER -D_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS ' +
+    '-I %{libcxx}/test/support -I %{libcxx}/src'
 ))
 config.substitutions.append(('%{link_flags}',
-    '-nostdlib++ -L %{install}/lib -lc++'
+    '-nostdlib++ -L %{install}/lib -lc++ -lc++abi'
 ))
 config.substitutions.append(('%{exec}',
-    '%{executor} --execdir %T --env DYLD_LIBRARY_PATH="%{cxx-runtime-root}:%{abi-runtime-root}" -- '
+    '%{executor} --execdir %T --env DYLD_LIBRARY_PATH="%{cxx-runtime-root}:%{abi-runtime-root}:%{unwind-runtime-root}" -- '
 ))
 
 libcxx.test.newconfig.configure(
diff --git a/libcxxabi/test/test_exception_address_alignment.pass.cpp b/libcxxabi/test/test_exception_address_alignment.pass.cpp
--- a/libcxxabi/test/test_exception_address_alignment.pass.cpp
+++ b/libcxxabi/test/test_exception_address_alignment.pass.cpp
@@ -11,9 +11,8 @@
 
 // The <unwind.h> header provided in the SDK of older Xcodes used to provide
 // an incorrectly aligned _Unwind_Exception type on non-ARM. That causes these
-// tests to fail when compiling against such a SDK, or when running against a
-// system libc++abi that was compiled with an incorrect definition of _Unwind_Exception.
-// XFAIL: apple-clang-12.0.0 && !target={{arm.*}}
+// tests to fail when running against a system libc++abi and libunwind that was
+// compiled with an incorrect definition of _Unwind_Exception.
 // XFAIL: use_system_cxx_lib && target={{.+}}-apple-macosx10.{{9|10|11|12}}
 
 // Test that the address of the exception object is properly aligned as required