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
@@ -230,24 +230,28 @@
 ;;
 generic-assertions)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-assertions.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-assertions.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
     check-abi-list
 ;;
 generic-debug-iterators)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-debug-iterators.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-debug-iterators.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
     check-abi-list
 ;;
 generic-noexceptions)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-noexceptions.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-noexceptions.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-modules)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-modules.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-modules.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-static)
@@ -258,21 +262,22 @@
 ;;
 generic-32bit)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-32bits.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-32bits.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-clang-11)
     export CC=clang-11
     export CXX=clang++-11
     clean
-    generate-cmake
+    generate-cmake -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-clang-12)
     export CC=clang-12
     export CXX=clang++-12
     clean
-    generate-cmake
+    generate-cmake -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-gcc)
@@ -291,52 +296,62 @@
 ;;
 generic-asan)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-asan.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-asan.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-msan)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-msan.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-msan.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-tsan)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-tsan.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-tsan.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-ubsan)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-ubsan.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-ubsan.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-with_llvm_unwinder)
     clean
-    generate-cmake -DLIBCXXABI_USE_LLVM_UNWINDER=ON
+    generate-cmake -DLIBCXXABI_USE_LLVM_UNWINDER=ON \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-singlethreaded)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-singlethreaded.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-singlethreaded.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-no-debug)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-debug.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-debug.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-no-filesystem)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-filesystem.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-filesystem.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-no-random_device)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-random_device.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-random_device.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-no-localization)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-localization.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-localization.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-no-unicode)
@@ -346,14 +361,16 @@
 ;;
 x86_64-apple-system)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Apple.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Apple.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 x86_64-apple-system-noexceptions)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Apple.cmake" \
                    -DLIBCXX_ENABLE_EXCEPTIONS=OFF \
-                   -DLIBCXXABI_ENABLE_EXCEPTIONS=OFF
+                   -DLIBCXXABI_ENABLE_EXCEPTIONS=OFF \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 x86_64-apple-system-backdeployment-*)
@@ -387,7 +404,7 @@
 ;;
 benchmarks)
     clean
-    generate-cmake
+    generate-cmake -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-benchmarks
 ;;
 documentation)
@@ -408,7 +425,8 @@
           -GNinja -DCMAKE_MAKE_PROGRAM="${NINJA}" \
           -DCMAKE_BUILD_TYPE=RelWithDebInfo \
           -DCMAKE_INSTALL_PREFIX="${INSTALL_DIR}" \
-          -DLLVM_ENABLE_PROJECTS="libcxx;libcxxabi;libunwind"
+          -DLLVM_ENABLE_PROJECTS="libcxx;libcxxabi;libunwind" \
+          -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
 
     check-cxx-cxxabi
 ;;
@@ -430,7 +448,8 @@
           -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi" \
           -DLLVM_RUNTIME_TARGETS="x86_64-unknown-linux-gnu" \
           -DLLVM_ENABLE_ASSERTIONS=ON \
-          -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-modules.cmake"
+          -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-modules.cmake" \
+          -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
 
     echo "+++ Running the libc++ and libc++abi tests"
     ${NINJA} -C "${BUILD_DIR}" check-runtimes
@@ -486,36 +505,42 @@
 ;;
 aarch64)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/AArch64.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/AArch64.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 aarch64-noexceptions)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/AArch64.cmake" \
                    -DLIBCXX_ENABLE_EXCEPTIONS=OFF \
-                   -DLIBCXXABI_ENABLE_EXCEPTIONS=OFF
+                   -DLIBCXXABI_ENABLE_EXCEPTIONS=OFF \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 # Aka Armv8 32 bit
 armv8)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv8Arm.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv8Arm.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 armv8-noexceptions)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv8Thumb-noexceptions.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv8Thumb-noexceptions.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 # Armv7 32 bit. One building Arm only one Thumb only code.
 armv7)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv7Arm.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv7Arm.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 armv7-noexceptions)
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv7Thumb-noexceptions.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv7Thumb-noexceptions.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 windows-dll)