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
@@ -237,7 +237,8 @@
     export CC=clang-tot
     export CXX=clang++-tot
     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="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
     check-abi-list
 ;;
@@ -245,7 +246,8 @@
     export CC=clang
     export CXX=clang++
     clean
-    generate-cmake -C "${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-static)
@@ -260,7 +262,8 @@
     export CC=clang
     export CXX=clang++
     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="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-gcc)
@@ -268,41 +271,45 @@
     export CXX=g++
     clean
     generate-cmake
-    check-cxx-cxxabi
+    check-cxx-cxxabi -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
 ;;
 generic-gcc-next)
     export CC=gcc-11
     export CXX=g++-11
     clean
     generate-cmake
-    check-cxx-cxxabi
+    check-cxx-cxxabi -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
 ;;
 generic-asan)
     export CC=clang
     export CXX=clang++
     clean
-    generate-cmake -C "${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)
     export CC=clang
     export CXX=clang++
     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="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-tsan)
     export CC=clang
     export CXX=clang++
     clean
-    generate-cmake -C "${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)
     export CC=clang
     export CXX=clang++
     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="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-with_llvm_unwinder)
@@ -316,42 +323,48 @@
     export CC=clang
     export CXX=clang++
     clean
-    generate-cmake -C "${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)
     export CC=clang
     export CXX=clang++
     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="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-no-filesystem)
     export CC=clang
     export CXX=clang++
     clean
-    generate-cmake -C "${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)
     export CC=clang
     export CXX=clang++
     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="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 generic-no-localization)
     export CC=clang
     export CXX=clang++
     clean
-    generate-cmake -C "${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
 ;;
 x86_64-apple-system)
     export CC=clang
     export CXX=clang++
     clean
-    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Apple.cmake"
+    generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Apple.cmake" \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 x86_64-apple-system-noexceptions)
@@ -360,7 +373,8 @@
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Apple.cmake" \
                    -DLIBCXX_ENABLE_EXCEPTIONS=OFF \
-                   -DLIBCXXABI_ENABLE_EXCEPTIONS=OFF
+                   -DLIBCXXABI_ENABLE_EXCEPTIONS=OFF \
+                   -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-cxxabi
 ;;
 x86_64-apple-system-backdeployment-*)
@@ -398,7 +412,7 @@
     export CC=clang
     export CXX=clang++
     clean
-    generate-cmake
+    generate-cmake -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
     check-cxx-benchmarks
 ;;
 documentation)
@@ -423,7 +437,8 @@
           -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
 ;;
@@ -442,7 +457,8 @@
           -DCMAKE_INSTALL_PREFIX="${INSTALL_DIR}" \
           -DLLVM_ENABLE_PROJECTS="clang" \
           -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi" \
-          -DLLVM_RUNTIME_TARGETS="x86_64-unknown-linux-gnu"
+          -DLLVM_RUNTIME_TARGETS="x86_64-unknown-linux-gnu" \
+          -DLIBCXX_TEST_CONFIG="${MONOREPO_ROOT}/libcxx/test/configs/libcxx-trunk-shared.cfg.in"
 
     echo "+++ Running the libc++ and libc++abi tests"
     ${NINJA} -C "${BUILD_DIR}" check-runtimes
@@ -503,36 +519,42 @@
 ;;
 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
+                   -DLIBCXX_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)