diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index a86ea0f7..72da96e1 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -403,6 +403,7 @@ jobs:
             export CC=clang
             export CXX=clang++
           fi
+          set +e
           cmake -B build "$GITHUB_WORKSPACE" "$CBT" -DSTANDALONE=ON \
               -DMAINTAINER_MODE=ON -DIWYU=ON \
               "-DSANITIZE_ADDRESS=${SANITIZE_ADDRESS}" \
@@ -410,6 +411,16 @@ jobs:
               "-DSANITIZE_UB=${SANITIZE_UB}" \
               "-DSTATIC_ANALYSIS=${STATIC_ANALYSIS}" "-DCOVERAGE=${COVERAGE}" \
               "-DAVX2=${AVX2}" "${EXTRA_CMAKE_ARGS[@]}"
+          CMAKE_EXIT_CODE=$?
+          set -e
+          if [ $CMAKE_EXIT_CODE -ne 0 ]; then
+            if [ -f build/CMakeFiles/CMakeConfigureLog.yaml ]; then
+              echo "::group::CMakeConfigureLog.yaml"
+              cat build/CMakeFiles/CMakeConfigureLog.yaml
+              echo "::endgroup::"
+            fi
+            exit $CMAKE_EXIT_CODE
+          fi
 
       - name: Build
         working-directory: ${{github.workspace}}/build
diff --git a/.github/workflows/old-compilers.yml b/.github/workflows/old-compilers.yml
index b52d7c26..4cfacf53 100644
--- a/.github/workflows/old-compilers.yml
+++ b/.github/workflows/old-compilers.yml
@@ -35,6 +35,98 @@ jobs:
       fail-fast: false
       matrix:
         include:
+          - name: clang 11 Release
+            BUILD_TYPE: Release
+            COMPILER: clang
+            VERSION: 11
+
+          - name: clang 11 Release with ASan
+            BUILD_TYPE: Release
+            SANITIZE_ADDRESS: ON
+            COMPILER: clang
+            VERSION: 11
+
+          - name: clang 11 Release with TSan
+            BUILD_TYPE: Release
+            SANITIZE_THREAD: ON
+            COMPILER: clang
+            VERSION: 11
+
+          - name: clang 11 Release with UBSan
+            BUILD_TYPE: Release
+            SANITIZE_UB: ON
+            COMPILER: clang
+            VERSION: 11
+
+          - name: clang 11 Debug
+            BUILD_TYPE: Debug
+            COMPILER: clang
+            VERSION: 11
+
+          - name: clang 11 Debug with ASan
+            BUILD_TYPE: Debug
+            SANITIZE_ADDRESS: ON
+            COMPILER: clang
+            VERSION: 11
+
+          - name: clang 11 Debug with TSan
+            BUILD_TYPE: Debug
+            SANITIZE_THREAD: ON
+            COMPILER: clang
+            VERSION: 11
+
+          - name: clang 11 Debug with UBSan
+            BUILD_TYPE: Debug
+            SANITIZE_UB: ON
+            COMPILER: clang
+            VERSION: 11
+
+          - name: clang 12 Release
+            BUILD_TYPE: Release
+            COMPILER: clang
+            VERSION: 12
+
+          - name: clang 12 Release with ASan
+            BUILD_TYPE: Release
+            SANITIZE_ADDRESS: ON
+            COMPILER: clang
+            VERSION: 12
+
+          - name: clang 12 Release with TSan
+            BUILD_TYPE: Release
+            SANITIZE_THREAD: ON
+            COMPILER: clang
+            VERSION: 12
+
+          - name: clang 12 Release with UBSan
+            BUILD_TYPE: Release
+            SANITIZE_UB: ON
+            COMPILER: clang
+            VERSION: 12
+
+          - name: clang 12 Debug
+            BUILD_TYPE: Debug
+            COMPILER: clang
+            VERSION: 12
+
+          - name: clang 12 Debug with ASan
+            BUILD_TYPE: Debug
+            SANITIZE_ADDRESS: ON
+            COMPILER: clang
+            VERSION: 12
+
+          - name: clang 12 Debug with TSan
+            BUILD_TYPE: Debug
+            SANITIZE_THREAD: ON
+            COMPILER: clang
+            VERSION: 12
+
+          - name: clang 12 Debug with UBSan
+            BUILD_TYPE: Debug
+            SANITIZE_UB: ON
+            COMPILER: clang
+            VERSION: 12
+
           - name: clang 13 Release
             BUILD_TYPE: Release
             COMPILER: clang
@@ -377,6 +469,52 @@ jobs:
             COMPILER: clang
             VERSION: 19
 
+          - name: GCC 10 Release
+            BUILD_TYPE: Release
+            COMPILER: gcc
+            VERSION: 10
+
+          - name: GCC 10 Release with ASan
+            BUILD_TYPE: Release
+            SANITIZE_ADDRESS: ON
+            COMPILER: gcc
+            VERSION: 10
+
+          - name: GCC 10 Release with TSan
+            BUILD_TYPE: Release
+            SANITIZE_THREAD: ON
+            COMPILER: gcc
+            VERSION: 10
+
+          - name: GCC 10 Release with UBSan
+            BUILD_TYPE: Release
+            SANITIZE_UB: ON
+            COMPILER: gcc
+            VERSION: 10
+
+          - name: GCC 10 Debug
+            BUILD_TYPE: Debug
+            COMPILER: gcc
+            VERSION: 10
+
+          - name: GCC 10 Debug with ASan
+            BUILD_TYPE: Debug
+            SANITIZE_ADDRESS: ON
+            COMPILER: gcc
+            VERSION: 10
+
+          - name: GCC 10 Debug with TSan
+            BUILD_TYPE: Debug
+            SANITIZE_THREAD: ON
+            COMPILER: gcc
+            VERSION: 10
+
+          - name: GCC 10 Debug with UBSan
+            BUILD_TYPE: Debug
+            SANITIZE_UB: ON
+            COMPILER: gcc
+            VERSION: 10
+
           - name: GCC 11 Release
             BUILD_TYPE: Release
             COMPILER: gcc
@@ -503,23 +641,27 @@ jobs:
         run: sudo apt-get install -y libboost-dev
         if: env.BOOST != 'OFF'
 
-      - name: Setup dependencies for LLVM 13 & 15+
+      - name: Setup LLVM 16+ repo
         run: |
           curl 'https://apt.llvm.org/llvm-snapshot.gpg.key' \
             | sudo apt-key add -
           sudo add-apt-repository -y \
             "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-${VERSION} main"
           sudo apt-get update
+        if: env.COMPILER == 'clang' && env.VERSION >= 16
+
+      - name: Setup dependencies for LLVM
+        run: |
           sudo apt-get install -y "llvm-${VERSION}-linker-tools" \
                 "clang-${VERSION}" "clang-tidy-${VERSION}"
-        if: >
-          env.COMPILER == 'clang'
-          && (env.VERSION == 13 || env.VERSION >= 15)
+        if: env.COMPILER == 'clang'
 
-      - name: Setup dependencies for GCC 12 (versioned package)
+      - name: Setup dependencies for GCC 10 & 12 (versioned packages)
         run: |
           sudo apt-get install -y "gcc-${VERSION}"
-        if: env.COMPILER == 'gcc' && env.VERSION == '12'
+        if: >
+          env.COMPILER == 'gcc'
+          && (env.VERSION == '10' || env.VERSION == '12')
 
       - name: Setup dependencies for GCC 11 (default OS package)
         run: |
@@ -555,6 +697,7 @@ jobs:
               EXTRA_CMAKE_ARGS=("${EXTRA_CMAKE_ARGS[@]}" "-DMAINTAINER_MODE=ON")
             fi
           fi
+          set +e
           cmake -B build "$GITHUB_WORKSPACE" -DSTANDALONE=ON \
               "-DCMAKE_BUILD_TYPE=$BUILD_TYPE" \
               "-DSANITIZE_ADDRESS=${SANITIZE_ADDRESS}" \
@@ -562,6 +705,16 @@ jobs:
               "-DSANITIZE_UB=${SANITIZE_UB}" \
               "-DSPINLOCK_LOOP=${SPINLOCK_LOOP}" "-DSTATS=${STATS}" \
               "${EXTRA_CMAKE_ARGS[@]}"
+          CMAKE_EXIT_CODE=$?
+          set -e
+          if [ $CMAKE_EXIT_CODE -ne 0 ]; then
+            if [ -f build/CMakeFiles/CMakeConfigureLog.yaml ]; then
+              echo "::group::CMakeConfigureLog.yaml"
+              cat build/CMakeFiles/CMakeConfigureLog.yaml
+              echo "::endgroup::"
+            fi
+          fi
+          exit $CMAKE_EXIT_CODE
 
       - name: Build
         working-directory: ${{github.workspace}}/build
diff --git a/.github/workflows/ubuntu-20.04.yml b/.github/workflows/ubuntu-20.04.yml
deleted file mode 100644
index 164e7ccd..00000000
--- a/.github/workflows/ubuntu-20.04.yml
+++ /dev/null
@@ -1,237 +0,0 @@
----
-name: build-ubuntu-20.04
-
-on:
-  push:
-    branches:
-      - master
-  pull_request:
-
-env:
-  DEFAULT_SANITIZE_ADDRESS: OFF
-  DEFAULT_SANITIZE_THREAD: OFF
-  DEFAULT_SANITIZE_UB: OFF
-
-permissions: {}
-
-jobs:
-  build:
-    runs-on: ubuntu-20.04
-
-    env:
-      BUILD_TYPE: ${{matrix.BUILD_TYPE}}
-      COMPILER: ${{matrix.COMPILER}}
-      VERSION: ${{matrix.VERSION}}
-      SANITIZE_ADDRESS: ${{matrix.SANITIZE_ADDRESS}}
-      SANITIZE_THREAD: ${{matrix.SANITIZE_THREAD}}
-      SANITIZE_UB: ${{matrix.SANITIZE_UB}}
-
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - name: clang 11 Release
-            BUILD_TYPE: Release
-            COMPILER: clang
-            VERSION: 11
-
-          - name: clang 11 Release with ASan
-            BUILD_TYPE: Release
-            SANITIZE_ADDRESS: ON
-            COMPILER: clang
-            VERSION: 11
-
-          - name: clang 11 Release with TSan
-            BUILD_TYPE: Release
-            SANITIZE_THREAD: ON
-            COMPILER: clang
-            VERSION: 11
-
-          - name: clang 11 Release with UBSan
-            BUILD_TYPE: Release
-            SANITIZE_UB: ON
-            COMPILER: clang
-            VERSION: 11
-
-          - name: clang 11 Debug
-            BUILD_TYPE: Debug
-            COMPILER: clang
-            VERSION: 11
-
-          - name: clang 11 Debug with ASan
-            BUILD_TYPE: Debug
-            SANITIZE_ADDRESS: ON
-            COMPILER: clang
-            VERSION: 11
-
-          - name: clang 11 Debug with TSan
-            BUILD_TYPE: Debug
-            SANITIZE_THREAD: ON
-            COMPILER: clang
-            VERSION: 11
-
-          - name: clang 11 Debug with UBSan
-            BUILD_TYPE: Debug
-            SANITIZE_UB: ON
-            COMPILER: clang
-            VERSION: 11
-
-          - name: clang 12 Release
-            BUILD_TYPE: Release
-            COMPILER: clang
-            VERSION: 12
-
-          - name: clang 12 Release with ASan
-            BUILD_TYPE: Release
-            SANITIZE_ADDRESS: ON
-            COMPILER: clang
-            VERSION: 12
-
-          - name: clang 12 Release with TSan
-            BUILD_TYPE: Release
-            SANITIZE_THREAD: ON
-            COMPILER: clang
-            VERSION: 12
-
-          - name: clang 12 Release with UBSan
-            BUILD_TYPE: Release
-            SANITIZE_UB: ON
-            COMPILER: clang
-            VERSION: 12
-
-          - name: clang 12 Debug
-            BUILD_TYPE: Debug
-            COMPILER: clang
-            VERSION: 12
-
-          - name: clang 12 Debug with ASan
-            BUILD_TYPE: Debug
-            SANITIZE_ADDRESS: ON
-            COMPILER: clang
-            VERSION: 12
-
-          - name: clang 12 Debug with TSan
-            BUILD_TYPE: Debug
-            SANITIZE_THREAD: ON
-            COMPILER: clang
-            VERSION: 12
-
-          - name: clang 12 Debug with UBSan
-            BUILD_TYPE: Debug
-            SANITIZE_UB: ON
-            COMPILER: clang
-            VERSION: 12
-
-          - name: GCC 10 Release
-            BUILD_TYPE: Release
-            COMPILER: gcc
-            VERSION: 10
-
-          - name: GCC 10 Release with ASan
-            BUILD_TYPE: Release
-            SANITIZE_ADDRESS: ON
-            COMPILER: gcc
-            VERSION: 10
-
-          - name: GCC 10 Release with TSan
-            BUILD_TYPE: Release
-            SANITIZE_THREAD: ON
-            COMPILER: gcc
-            VERSION: 10
-
-          - name: GCC 10 Release with UBSan
-            BUILD_TYPE: Release
-            SANITIZE_UB: ON
-            COMPILER: gcc
-            VERSION: 10
-
-          - name: GCC 10 Debug
-            BUILD_TYPE: Debug
-            COMPILER: gcc
-            VERSION: 10
-
-          - name: GCC 10 Debug with ASan
-            BUILD_TYPE: Debug
-            SANITIZE_ADDRESS: ON
-            COMPILER: gcc
-            VERSION: 10
-
-          - name: GCC 10 Debug with TSan
-            BUILD_TYPE: Debug
-            SANITIZE_THREAD: ON
-            COMPILER: gcc
-            VERSION: 10
-
-          - name: GCC 10 Debug with UBSan
-            BUILD_TYPE: Debug
-            SANITIZE_UB: ON
-            COMPILER: gcc
-            VERSION: 10
-
-
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          submodules: true
-
-      - name: Setup common dependencies
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y libboost-dev libc6-dev-i386
-
-      - name: Setup dependencies for GCC
-        run: |
-          sudo apt-get install -y "gcc-${VERSION}" "gcc-${VERSION}-multilib"
-        if: env.COMPILER == 'gcc'
-
-      - name: Setup dependencies for LLVM (common)
-        run: |
-          sudo apt-get install -y "clang-${VERSION}" "clang-tidy-${VERSION}"
-        if: env.COMPILER == 'clang'
-
-      - name: Setup dependencies for LLVM (Release)
-        run: |
-          sudo apt-get install -y "libomp5-${VERSION}" "llvm-${VERSION}" \
-               "lld-${VERSION}"
-        if: env.COMPILER == 'clang' && env.BUILD_TYPE == 'Release'
-
-      - name: Configure CMake
-        # Use a bash shell so we can use the same syntax for environment
-        # variable access regardless of the host operating system
-        shell: bash
-        run: |
-          SANITIZE_ADDRESS="${SANITIZE_ADDRESS:-$DEFAULT_SANITIZE_ADDRESS}"
-          SANITIZE_THREAD="${SANITIZE_THREAD:-$DEFAULT_SANITIZE_THREAD}"
-          SANITIZE_UB="${SANITIZE_UB:-$DEFAULT_SANITIZE_UB}"
-          if [[ $COMPILER == "gcc" ]]; then
-            export CC="gcc-${VERSION}"
-            export CXX="g++-${VERSION}"
-            EXTRA_CMAKE_ARGS=("-DMAINTAINER_MODE=ON")
-          else
-            export CC="clang-${VERSION}"
-            export CXX="clang++-${VERSION}"
-            EXTRA_CMAKE_ARGS=("-DCLANG_TIDY_EXE=/usr/bin/clang-tidy-${VERSION}")
-            if [[ $BUILD_TYPE == "Release" ]]; then
-              EXTRA_CMAKE_ARGS=("${EXTRA_CMAKE_ARGS[@]}" \
-                  "-DLLVMAR_EXECUTABLE=/usr/bin/llvm-ar-${VERSION}" \
-                  "-DLLVMNM_EXECUTABLE=/usr/bin/llvm-nm-${VERSION}" \
-                  "-DLLVMRANLIB_EXECUTABLE=/usr/bin/llvm-ranlib-${VERSION}")
-            fi
-          fi
-          cmake -B build "$GITHUB_WORKSPACE" -DSTANDALONE=ON \
-              "-DCMAKE_BUILD_TYPE=$BUILD_TYPE" \
-              "-DSANITIZE_ADDRESS=${SANITIZE_ADDRESS}" \
-              "-DSANITIZE_THREAD=${SANITIZE_THREAD}" \
-              "-DSANITIZE_UB=${SANITIZE_UB}" "${EXTRA_CMAKE_ARGS[@]}"
-
-      - name: Build
-        working-directory: ${{github.workspace}}/build
-        run: make -j3 -k
-
-      - name: Correctness test
-        working-directory: ${{github.workspace}}/build
-        run: ctest -j3 -V
-
-      - name: Benchmark correctness test
-        working-directory: ${{github.workspace}}/build
-        run: make -k quick_benchmarks
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9fd4af39..8f058b8a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,6 +28,9 @@ set_bool(is_x86_64 "${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "AMD64"
   OR "${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "x86_64")
 set_bool(is_apple_clang "${CMAKE_CXX_COMPILER_ID}" STREQUAL "AppleClang")
 set_bool(is_clang "${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
+set_bool(is_clang11 ${is_clang}
+  AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 11.0
+  AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 12.0)
 set_bool(is_gxx "${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
 set_bool(is_any_clang ${is_apple_clang} OR ${is_clang})
 
@@ -288,15 +291,29 @@ if(SANITIZE_UB)
     # conversions do not appear to be fully suppressable
     list(APPEND SANITIZER_CXX_FLAGS "-fsanitize=local-bounds"
       "-fsanitize=nullability")
-    if(is_clang AND CMAKE_CXX_COMPILE_VERSION VERSION_GREATER_EQUAL 19.0)
+    if(is_clang AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 19.0)
       list(APPEND SANITIZER_CXX_FLAGS "-fsanitize=implicit-bitfield-conversion")
     endif()
   endif()
+
   set(SANITIZER_LD_FLAGS "-fsanitize=undefined")
+
   string(CONCAT UBSAN_ENV "UBSAN_OPTIONS="
     "print_stacktrace=1:halt_on_error=1:abort_on_error=1")
+
+  # clang 11 as packaged in Ubuntu 22.04 needs a workaround for
+  # https://github.com/llvm/llvm-project/issues/55785
+  if(is_clang11)
+    string(APPEND UBSAN_ENV ":use_sigaltstack=false")
+  endif()
+
   list(APPEND SANITIZER_ENV ${UBSAN_ENV})
   unset(UBSAN_ENV)
+elseif(is_clang11)
+  # Even though the sanitizer is not enabled here, DeepState will enable it
+  # itself, and clang 11 as packaged in Ubuntu 22.04, needs a workaround for
+  # https://github.com/llvm/llvm-project/issues/55785
+  list(APPEND SANITIZER_ENV "UBSAN_OPTIONS=use_sigaltstack=false")
 endif()
 
 message(STATUS "SANITIZER_ENV: ${SANITIZER_ENV}")
@@ -554,6 +571,20 @@ if(BENCHMARKS)
       endif()
     endif()
 
+    if(is_clang11)
+      # clang 11 as packaged in Ubuntu 22.04 needs a configure-time workaround
+      # for https://github.com/llvm/llvm-project/issues/55785
+      if(SANITIZE_ADDRESS)
+        set(ENV{ASAN_OPTIONS} "use_sigaltstack=false")
+      endif()
+      if(SANITIZE_THREAD)
+        set(ENV{TSAN_OPTIONS} "use_sigaltstack=false")
+      endif()
+      if(SANITIZE_UB)
+        set(ENV{UBSAN_OPTIONS} "use_sigaltstack=false")
+      endif()
+    endif()
+
     ADD_CXX_FLAGS_FOR_SUBDIR()
     add_subdirectory(3rd_party/benchmark)
     RESTORE_CXX_FLAGS_FOR_SUBDIR()
@@ -798,7 +829,12 @@ if(TESTS)
   function(add_sanitized_test)
     cmake_parse_arguments(AST "" "NAME" "COMMAND" ${ARGN})
     add_test(NAME "${AST_NAME}" COMMAND ${AST_COMMAND})
-    if(SANITIZE_ADDRESS OR SANITIZE_THREAD OR SANITIZE_UB)
+    # Set Sanitizer environment on a sanitizer-less build too, if using clang
+    # 11 and DeepState is built, because it enables sanitizers itself. clang 11
+    # handling is to workaround
+    # https://github.com/llvm/llvm-project/issues/55785 on Ubuntu 22.04.
+    if(SANITIZE_ADDRESS OR SANITIZE_THREAD OR SANITIZE_UB
+        OR (TARGET deepstate AND is_clang11))
       set_property(TEST "${AST_NAME}" APPEND PROPERTY ENVIRONMENT
         "${SANITIZER_ENV}")
     endif()