diff --git a/.github/actions/compilers/action.yml b/.github/actions/compilers/action.yml
new file mode 100644
index 00000000000000..ecb8e4f485168b
--- /dev/null
+++ b/.github/actions/compilers/action.yml
@@ -0,0 +1,94 @@
+name: Compiles ruby in a container
+description: >-
+  Makes ruby using a dedicated container
+
+inputs:
+  tag:
+    required: false
+    default: clang-18
+    description: >-
+      container image tag to use in this run.
+
+  with_gcc:
+    required: false
+    description: >-
+      override compiler path & flags.
+
+  CFLAGS:
+    required: false
+    description: >-
+      C compiler flags to override.
+
+  CXXFLAGS:
+    required: false
+    description: >-
+      C++ compiler flags to override.
+
+  optflags:
+    required: false
+    # -O1 is faster than -O3 in our tests... Majority of time are consumed trying
+    # to optimize binaries.  Also GitHub Actions run on relatively modern CPUs
+    # compared to, say, GCC 4 or Clang 3.  We don't specify `-march=native`
+    # because compilers tend not understand what the CPU is.
+    default: '-O1'
+    description: >-
+      Compiler flags for optimisations.
+
+  cppflags:
+    required: false
+    description: >-
+      Additional preprocessor flags.
+
+  append_configure:
+    required: false
+    default: >-
+      --without-valgrind
+      --without-jemalloc
+      --without-gmp
+    description: >-
+      flags to append to configure.
+
+  enable_shared:
+    required: false
+    default: true
+    description: >-
+      Whether to build libruby.so.
+
+  check:
+    required: false
+    default: ''
+    description: >-
+      Whether to run `make check`
+
+  static_exts:
+    required: false
+    description: >-
+      whitespace separated list of extensions that need be linked statically.
+
+runs:
+  using: composite
+  steps:
+    - shell: bash
+      run: docker pull --quiet 'ghcr.io/ruby/ruby-ci-image:${{ inputs.tag }}'
+
+    - name: compile
+      shell: bash
+      run: >-
+        docker run
+        --rm
+        --user=root
+        --volume '${{ github.workspace }}:/github/workspace:ro'
+        --workdir=/github/workspace
+        --entrypoint=/github/workspace/.github/actions/compilers/entrypoint.sh
+        --env CI
+        --env GITHUB_ACTION
+        --env INPUT_WITH_GCC='${{ inputs.with_gcc || inputs.tag }}'
+        --env INPUT_CFLAGS='${{ inputs.CFLAGS }}'
+        --env INPUT_CXXFLAGS='${{ inputs.CXXFLAGS }}'
+        --env INPUT_OPTFLAGS='${{ inputs.OPTFLAGS }}'
+        --env INPUT_CPPFLAGS='${{ inputs.cppflags }}'
+        --env INPUT_APPEND_CONFIGURE='${{ inputs.append_configure }}'
+        --env INPUT_CHECK='${{ inputs.check }}'
+        --env INPUT_ENABLE_SHARED='${{ inputs.enable_shared }}'
+        --env INPUT_STATIC_EXTS='${{ inputs.static_exts }}'
+        'ghcr.io/ruby/ruby-ci-image:${{ inputs.tag }}'
diff --git a/.github/actions/compilers/entrypoint.sh b/.github/actions/compilers/entrypoint.sh
new file mode 100755
index 00000000000000..8e5b93f3997c85
--- /dev/null
+++ b/.github/actions/compilers/entrypoint.sh
@@ -0,0 +1,90 @@
+#! /bin/bash
+
+# Copyright (c) 2024 Ruby developers.  All rights reserved.
+#
+# This file is  a part of the programming language  Ruby.  Permission is hereby
+# granted, to  either redistribute and/or  modify this file, provided  that the
+# conditions  mentioned in  the file  COPYING are  met.  Consult  the file  for
+# details.
+
+grouped()
+{
+    echo "::group::${@}"
+    "${@}"
+    echo "::endgroup::"
+}
+
+set -e
+set -u
+set -o pipefail
+
+srcdir="/github/workspace/src"
+builddir="$(mktemp -dt)"
+
+export GITHUB_WORKFLOW='Compilations'
+export CONFIGURE_TTY='never'
+export RUBY_DEBUG='ci rgengc'
+export RUBY_TESTOPTS='-q --color=always --tty=no'
+export RUBY_DEBUG_COUNTER_DISABLE='1'
+export GNUMAKEFLAGS="-j$((1 + $(nproc --all)))"
+
+case "x${INPUT_ENABLE_SHARED}" in
+x | xno | xfalse )
+    enable_shared='--disable-shared'
+    ;;
+*)
+    enable_shared='--enable-shared'
+    ;;
+esac
+
+pushd ${builddir}
+
+grouped ${srcdir}/configure        \
+    -C                             \
+    --with-gcc="${INPUT_WITH_GCC}" \
+    --enable-debug-env             \
+    --disable-install-doc          \
+    --with-ext=-test-/cxxanyargs,+ \
+    ${enable_shared}               \
+    ${INPUT_APPEND_CONFIGURE}      \
+    CFLAGS="${INPUT_CFLAGS}"       \
+    CXXFLAGS="${INPUT_CXXFLAGS}"   \
+    optflags="${INPUT_OPTFLAGS}"   \
+    cppflags="${INPUT_CPPFLAGS}"   \
+    debugflags='-ggdb3' # -g0 disables backtraces when SEGV.  Do not set that.
+
+popd
+
+if [[ -n "${INPUT_STATIC_EXTS}" ]]; then
+    echo "::group::ext/Setup"
+    set -x
+    mkdir ${builddir}/ext
+    (
+        for ext in ${INPUT_STATIC_EXTS}; do
+            echo "${ext}"
+        done
+    ) >> ${builddir}/ext/Setup
+    set +x
+    echo "::endgroup::"
+fi
+
+pushd ${builddir}
+
+case "${INPUT_APPEND_CONFIGURE}" in
+*--with-shared-gc*)
+    export RUBY_GC_LIBRARY='librubygc.default.so'
+    mkdir -p /home/runner/shared-gc
+    grouped make shared-gc SHARED_GC=default
+    ;;
+esac
+
+grouped make showflags
+grouped make all
+grouped make test
+
+[[ -z "${INPUT_CHECK}" ]] && exit 0
+
+grouped make install
+grouped make test-tool
+grouped make test-all TESTS='-- ruby -ext-'
+grouped env CHECK_LEAKS=true make test-spec
diff --git a/.github/actions/setup/directories/action.yml b/.github/actions/setup/directories/action.yml
index 46691778bf3616..edf83fa13b1ea8 100644
--- a/.github/actions/setup/directories/action.yml
+++ b/.github/actions/setup/directories/action.yml
@@ -101,7 +101,7 @@ runs:
     - if: steps.which.outputs.autoreconf
       shell: bash
       working-directory: ${{ inputs.srcdir }}
-      run: ./autogen.sh
+      run: ./autogen.sh --install
 
     # This is for MinGW.
     - if: runner.os == 'Windows'
diff --git a/.github/workflows/compilers.yml b/.github/workflows/compilers.yml
index 9a3f2f2cd08e41..8999498d04e4a4 100644
--- a/.github/workflows/compilers.yml
+++ b/.github/workflows/compilers.yml
@@ -24,200 +24,14 @@ concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
   cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
 
-# GitHub actions does not support YAML anchors.  This creative use of
-# environment variables (plus the "echo $GITHUB_ENV" hack) is to reroute that
-# restriction.
-env:
-  default_cc: clang-18
-  append_cc: ''
-
-  # -O1 is faster than -O3 in our tests... Majority of time are consumed trying
-  # to optimize binaries.  Also GitHub Actions run on relatively modern CPUs
-  # compared to, say, GCC 4 or Clang 3.  We don't specify `-march=native`
-  # because compilers tend not understand what the CPU is.
-  optflags: '-O1'
-
-  # -g0 disables backtraces when SEGV.  Do not set that.
-  debugflags: '-ggdb3'
-
-  default_configure: >-
-    --enable-debug-env
-    --disable-install-doc
-    --with-ext=-test-/cxxanyargs,+
-  append_configure: >-
-    --without-valgrind
-    --without-jemalloc
-    --without-gmp
-
-  CONFIGURE_TTY: never
-  GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
-  RUBY_DEBUG: ci rgengc
-  RUBY_TESTOPTS: >-
-    -q
-    --color=always
-    --tty=no
-
 permissions:
   contents: read
 
+# Each job is split so that they roughly take 30min to run through.
 jobs:
-  compile:
-    strategy:
-      fail-fast: false
-      matrix:
-        env:
-          - {}
-        entry:
-          - { name: gcc-13,    env: { default_cc: gcc-13 } }
-          - { name: gcc-12,    env: { default_cc: gcc-12 } }
-          - { name: gcc-11,    env: { default_cc: gcc-11 } }
-          - { name: gcc-10,    env: { default_cc: gcc-10 } }
-          - { name: gcc-9,     env: { default_cc: gcc-9 } }
-          - { name: gcc-8,     env: { default_cc: gcc-8 } }
-          - { name: gcc-7,     env: { default_cc: gcc-7 } }
-          - name: 'gcc-13 LTO'
-            container: gcc-13
-            env:
-              default_cc: 'gcc-13 -flto=auto -ffat-lto-objects -Werror=lto-type-mismatch'
-              optflags: '-O2'
-            shared: disable
-            # check: true
-          - { name: clang-19,  env: { default_cc: clang-19 } }
-          - { name: clang-18,  env: { default_cc: clang-18 } }
-          - { name: clang-17,  env: { default_cc: clang-17 } }
-          - { name: clang-16,  env: { default_cc: clang-16 } }
-          - { name: clang-15,  env: { default_cc: clang-15 } }
-          - { name: clang-14,  env: { default_cc: clang-14 } }
-          - { name: clang-13,  env: { default_cc: clang-13 } }
-          - { name: clang-12,  env: { default_cc: clang-12 } }
-          - { name: clang-11,  env: { default_cc: clang-11 } }
-          - { name: clang-10,  env: { default_cc: clang-10 } }
-          # llvm-objcopy<=9 doesn't have --wildcard. It compiles, but leaves Rust symbols in libyjit.o.
-          - { name: clang-9,   env: { default_cc: clang-9,   append_configure: '--disable-yjit' } }
-          - { name: clang-8,   env: { default_cc: clang-8,   append_configure: '--disable-yjit' } }
-          - { name: clang-7,   env: { default_cc: clang-7,   append_configure: '--disable-yjit' } }
-          - { name: clang-6.0, env: { default_cc: clang-6.0, append_configure: '--disable-yjit' } }
-          - name: 'clang-16 LTO'
-            container: clang-16
-            env:
-              default_cc: 'clang-16 -flto=auto'
-              optflags: '-O2'
-            shared: disable
-            # check: true
-
-          - { name: ext/Setup, static-exts: 'etc,json/*,*/escape' }
-
-#         - { name: aarch64-linux-gnu,     crosshost: aarch64-linux-gnu, container: crossbuild-essential-arm64 }
-#         - { name: arm-linux-gnueabi,     crosshost: arm-linux-gnueabi }
-#         - { name: arm-linux-gnueabihf,   crosshost: arm-linux-gnueabihf }
-#         - { name: i686-w64-mingw32,      crosshost: i686-w64-mingw32 }
-#         - { name: powerpc-linux-gnu,     crosshost: powerpc-linux-gnu }
-#         - { name: powerpc64le-linux-gnu, crosshost: powerpc64le-linux-gnu, container: crossbuild-essential-ppc64el }
-#         - { name: s390x-linux-gnu,       crosshost: s390x-linux-gnu, container: crossbuild-essential-s390x }
-#         - { name: x86_64-w64-mingw32,    crosshost: x86_64-w64-mingw32, container: mingw-w64 }
-
-          # -Wno-strict-prototypes is necessary with current clang-15 since
-          # older autoconf generate functions without prototype and -pedantic
-          # now implies strict-prototypes. Disabling the error but leaving the
-          # warning generates a lot of noise from use of ANYARGS in
-          # rb_define_method() and friends.
-          # See: https://github.com/llvm/llvm-project/commit/11da1b53d8cd3507959022cd790d5a7ad4573d94
-          - { name: c99,   env: { CFLAGS:   '-std=c99   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
-#         - { name: c11,   env: { CFLAGS:   '-std=c11   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
-#         - { name: c17,   env: { CFLAGS:   '-std=c17   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
-          - { name: c23,   env: { CFLAGS:   '-std=c2x   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
-          - { name: c++98, env: { CXXFLAGS: '-std=c++98 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-#         - { name: c++11, env: { CXXFLAGS: '-std=c++11 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-#         - { name: c++14, env: { CXXFLAGS: '-std=c++14 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-#         - { name: c++17, env: { CXXFLAGS: '-std=c++17 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-#         - { name: c++20, env: { CXXFLAGS: '-std=c++20 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-#         - { name: c++23, env: { CXXFLAGS: '-std=c++23 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-          - { name: c++26, env: { CXXFLAGS: '-std=c++26 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-
-          - { name: '-O0', env: { optflags: '-O0 -march=x86-64 -mtune=generic' } }
-#         - { name: '-O3', env: { optflags: '-O3 -march=x86-64 -mtune=generic' }, check: true }
-
-          - { name: gmp,                  env: { append_configure: '--with-gmp' }, check: true }
-          - { name: jemalloc,             env: { append_configure: '--with-jemalloc' } }
-          - { name: valgrind,             env: { append_configure: '--with-valgrind' } }
-          - { name: 'coroutine=ucontext', env: { append_configure: '--with-coroutine=ucontext' } }
-          - { name: 'coroutine=pthread',  env: { append_configure: '--with-coroutine=pthread' } }
-          - { name: disable-jit,          env: { append_configure: '--disable-yjit --disable-rjit' } }
-          - { name: disable-dln,          env: { append_configure: '--disable-dln' } }
-          - { name: enable-mkmf-verbose,  env: { append_configure: '--enable-mkmf-verbose' } }
-          - { name: disable-rubygems,     env: { append_configure: '--disable-rubygems' } }
-          - { name: RUBY_DEVEL,           env: { append_configure: '--enable-devel' } }
-
-          - { name: OPT_THREADED_CODE=0,            env: { cppflags: '-DOPT_THREADED_CODE=0' } }
-          - { name: OPT_THREADED_CODE=1,            env: { cppflags: '-DOPT_THREADED_CODE=1' } }
-          - { name: OPT_THREADED_CODE=2,            env: { cppflags: '-DOPT_THREADED_CODE=2' } }
-
-          - { name: NDEBUG,                         env: { cppflags: '-DNDEBUG' } }
-          - { name: RUBY_DEBUG,                     env: { cppflags: '-DRUBY_DEBUG' } }
-#         - { name: ARRAY_DEBUG,                    env: { cppflags: '-DARRAY_DEBUG' } }
-#         - { name: BIGNUM_DEBUG,                   env: { cppflags: '-DBIGNUM_DEBUG' } }
-#         - { name: CCAN_LIST_DEBUG,                env: { cppflags: '-DCCAN_LIST_DEBUG' } }
-#         - { name: CPDEBUG=-1,                     env: { cppflags: '-DCPDEBUG=-1' } }
-#         - { name: ENC_DEBUG,                      env: { cppflags: '-DENC_DEBUG' } }
-#         - { name: GC_DEBUG,                       env: { cppflags: '-DGC_DEBUG' } }
-#         - { name: HASH_DEBUG,                     env: { cppflags: '-DHASH_DEBUG' } }
-#         - { name: ID_TABLE_DEBUG,                 env: { cppflags: '-DID_TABLE_DEBUG' } }
-#         - { name: RGENGC_DEBUG=-1,                env: { cppflags: '-DRGENGC_DEBUG=-1' } }
-#         - { name: SYMBOL_DEBUG,                   env: { cppflags: '-DSYMBOL_DEBUG' } }
-
-#         - { name: RGENGC_CHECK_MODE,              env: { cppflags: '-DRGENGC_CHECK_MODE' } }
-#         - { name: VM_CHECK_MODE,                  env: { cppflags: '-DVM_CHECK_MODE' } }
-
-#         - { name: USE_EMBED_CI=0,                 env: { cppflags: '-DUSE_EMBED_CI=0' } }
-          - name: USE_FLONUM=0
-            env:
-              cppflags: '-DUSE_FLONUM=0'
-              # yjit requires FLONUM for the pointer tagging scheme
-              append_configure: '--disable-yjit'
-#         - { name: USE_GC_MALLOC_OBJ_INFO_DETAILS, env: { cppflags: '-DUSE_GC_MALLOC_OBJ_INFO_DETAILS' } }
-#         - { name: USE_LAZY_LOAD,                  env: { cppflags: '-DUSE_LAZY_LOAD' } }
-#         - { name: USE_SYMBOL_GC=0,                env: { cppflags: '-DUSE_SYMBOL_GC=0' } }
-#         - { name: USE_THREAD_CACHE=0,             env: { cppflags: '-DUSE_THREAD_CACHE=0' } }
-          - { name: USE_RUBY_DEBUG_LOG=1,           env: { cppflags: '-DUSE_RUBY_DEBUG_LOG=1' } }
-#         - { name: USE_DEBUG_COUNTER,              env: { cppflags: '-DUSE_DEBUG_COUNTER=1', RUBY_DEBUG_COUNTER_DISABLE: '1' } }
-          - { name: SHARABLE_MIDDLE_SUBSTRING,      env: { cppflags: '-DSHARABLE_MIDDLE_SUBSTRING=1' } }
-
-#         - { name: DEBUG_FIND_TIME_NUMGUESS,       env: { cppflags: '-DDEBUG_FIND_TIME_NUMGUESS' } }
-#         - { name: DEBUG_INTEGER_PACK,             env: { cppflags: '-DDEBUG_INTEGER_PACK' } }
-#         - { name: ENABLE_PATH_CHECK,              env: { cppflags: '-DENABLE_PATH_CHECK' } }
-
-#         - { name: GC_DEBUG_STRESS_TO_CLASS,       env: { cppflags: '-DGC_DEBUG_STRESS_TO_CLASS' } }
-#         - { name: GC_ENABLE_LAZY_SWEEP=0,         env: { cppflags: '-DGC_ENABLE_LAZY_SWEEP=0' } }
-#         - { name: GC_PROFILE_DETAIL_MEMOTY,       env: { cppflags: '-DGC_PROFILE_DETAIL_MEMOTY' } }
-#         - { name: GC_PROFILE_MORE_DETAIL,         env: { cppflags: '-DGC_PROFILE_MORE_DETAIL' } }
-
-#         - { name: CALC_EXACT_MALLOC_SIZE,         env: { cppflags: '-DCALC_EXACT_MALLOC_SIZE' } }
-#         - { name: MALLOC_ALLOCATED_SIZE_CHECK,    env: { cppflags: '-DMALLOC_ALLOCATED_SIZE_CHECK' } }
-
-#         - { name: IBF_ISEQ_ENABLE_LOCAL_BUFFER,   env: { cppflags: '-DIBF_ISEQ_ENABLE_LOCAL_BUFFER' } }
-
-#         - { name: RGENGC_ESTIMATE_OLDMALLOC,      env: { cppflags: '-DRGENGC_ESTIMATE_OLDMALLOC' } }
-#         - { name: RGENGC_FORCE_MAJOR_GC,          env: { cppflags: '-DRGENGC_FORCE_MAJOR_GC' } }
-#         - { name: RGENGC_OBJ_INFO,                env: { cppflags: '-DRGENGC_OBJ_INFO' } }
-#         - { name: RGENGC_PROFILE,                 env: { cppflags: '-DRGENGC_PROFILE' } }
-
-#         - { name: VM_DEBUG_BP_CHECK,              env: { cppflags: '-DVM_DEBUG_BP_CHECK' } }
-#         - { name: VM_DEBUG_VERIFY_METHOD_CACHE,   env: { cppflags: '-DVM_DEBUG_VERIFY_METHOD_CACHE' } }
-
-          - { name: enable-yjit,                    env: { append_configure: '--enable-yjit --disable-rjit' } }
-          - { name: enable-rjit,                    env: { append_configure: '--enable-rjit --disable-yjit' } }
-          - { name: YJIT_FORCE_ENABLE,              env: { cppflags: '-DYJIT_FORCE_ENABLE' } }
-#         - { name: RJIT_FORCE_ENABLE,              env: { cppflags: '-DRJIT_FORCE_ENABLE' } }
-          - { name: UNIVERSAL_PARSER,               env: { cppflags: '-DUNIVERSAL_PARSER' } }
-
-    name: ${{ matrix.entry.name }}
-
+  compile1:
+    name: 'omnibus compilations, #1'
     runs-on: ubuntu-latest
-
-    container:
-      image: ghcr.io/ruby/ruby-ci-image:${{ matrix.entry.container || matrix.entry.env.default_cc || 'clang-18' }}
-      options: --user root
-
     if: >-
       ${{!(false
       || contains(github.event.head_commit.message, '[DOC]')
@@ -227,78 +41,347 @@ jobs:
       || contains(github.event.pull_request.labels.*.name, 'Document')
       || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
       )}}
-
-    env: ${{ matrix.entry.env || matrix.env }}
-
+    services: { docuum: { image: 'stephanmisc/docuum', options: '--init', volumes: [ '/root', '/var/run/docker.sock:/var/run/docker.sock' ] } }
     steps:
-      - run: id
-        working-directory:
-
       - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true } }
+      - name: 'clang 16 LTO'
+        uses: './.github/actions/compilers'
         with:
-          sparse-checkout-cone-mode: false
-          sparse-checkout: /.github
-
-      - uses: ./.github/actions/setup/directories
-        with:
-          srcdir: src
-          builddir: build
-          makeup: true
-          clean: true
-
-      - name: Run configure
-        run: >
-          ../src/configure -C ${default_configure} ${append_configure}
-          --${{
-            matrix.entry.crosshost && 'host' || 'with-gcc'
-          }}=${{
-            matrix.entry.crosshost || '"${default_cc}${append_cc:+ $append_cc}"'
-          }}
-          --${{ matrix.entry.shared || 'enable' }}-shared
-
-      - name: Add to ext/Setup
-        id: ext-setup
-        run: |
-          mkdir ext
-          cd ext
-          for ext in {${{ matrix.entry.static-exts }}}; do
-            echo "${ext}"
-          done >> Setup
-        if: ${{ (matrix.entry.static-exts || '') != '' }}
-
-      - name: Clean up ext/Setup
-        uses: gacts/run-and-post-run@4683764dd706df847f57b9bed39d08164bcd2690 # v1.4.1
+          tag: clang-16
+          with_gcc: 'clang-16 -flto=auto'
+          optflags: '-O2'
+          enable_shared: false
+      - name: 'GCC 13 LTO'
+        uses: './.github/actions/compilers'
         with:
-          shell: bash
-          working-directory: build
-          post: rm ext/Setup
-        if: ${{ steps.ext-setup.outcome == 'success' }}
-
-      - run: make showflags
-
-      - run: make
-
-      - run: make test
-
-      - run: make install
-        if: ${{ matrix.entry.check }}
-
-      - run: make test-tool
-        if: ${{ matrix.entry.check }}
-
-      - run: make test-all TESTS='-- ruby -ext-'
-        if: ${{ matrix.entry.check }}
-
-      - run: make test-spec
-        env:
-          CHECK_LEAKS: true
-        if: ${{ matrix.entry.check }}
+          tag: gcc-13
+          with_gcc: 'gcc-13 -flto=auto -ffat-lto-objects -Werror=lto-type-mismatch'
+          optflags: '-O2'
+          enable_shared: false
 
+  compile2:
+    name: 'omnibus compilations, #2'
+    runs-on: ubuntu-latest
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Document')
+      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      )}}
+    services: { docuum: { image: 'stephanmisc/docuum', options: '--init', volumes: [ '/root', '/var/run/docker.sock:/var/run/docker.sock' ] } }
+    steps:
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true } }
+      - { uses: './.github/actions/compilers', name: 'GCC 13', with: { tag: 'gcc-13' } }
+      - { uses: './.github/actions/compilers', name: 'GCC 12', with: { tag: 'gcc-12' } }
+      - { uses: './.github/actions/compilers', name: 'GCC 11', with: { tag: 'gcc-11' } }
+      - { uses: './.github/actions/compilers', name: 'GCC 10', with: { tag: 'gcc-10' } }
+      - { uses: './.github/actions/compilers', name: 'GCC 9',  with: { tag: 'gcc-9'  } }
+      - { uses: './.github/actions/compilers', name: 'GCC 8',  with: { tag: 'gcc-8'  } }
+      - { uses: './.github/actions/compilers', name: 'GCC 7',  with: { tag: 'gcc-7'  } }
+
+  compile3:
+    name: 'omnibus compilations, #3'
+    runs-on: ubuntu-latest
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Document')
+      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      )}}
+    services: { docuum: { image: 'stephanmisc/docuum', options: '--init', volumes: [ '/root', '/var/run/docker.sock:/var/run/docker.sock' ] } }
+    steps:
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true } }
+      - { uses: './.github/actions/compilers', name: 'clang 19', with: { tag: 'clang-19' } }
+      - { uses: './.github/actions/compilers', name: 'clang 18', with: { tag: 'clang-18' } }
+      - { uses: './.github/actions/compilers', name: 'clang 17', with: { tag: 'clang-17' } }
+      - { uses: './.github/actions/compilers', name: 'clang 16', with: { tag: 'clang-16' } }
+      - { uses: './.github/actions/compilers', name: 'clang 15', with: { tag: 'clang-15' } }
+      - { uses: './.github/actions/compilers', name: 'clang 14', with: { tag: 'clang-14' } }
+      - { uses: './.github/actions/compilers', name: 'clang 13', with: { tag: 'clang-13' } }
+      - { uses: './.github/actions/compilers', name: 'clang 12', with: { tag: 'clang-12' } }
+
+  compile4:
+    name: 'omnibus compilations, #4'
+    runs-on: ubuntu-latest
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Document')
+      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      )}}
+    services: { docuum: { image: 'stephanmisc/docuum', options: '--init', volumes: [ '/root', '/var/run/docker.sock:/var/run/docker.sock' ] } }
+    steps:
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true } }
+      - { uses: './.github/actions/compilers', name: 'clang 11', with: { tag: 'clang-11' } }
+      - { uses: './.github/actions/compilers', name: 'clang 10', with: { tag: 'clang-10' } }
+        # llvm-objcopy<=9 doesn't have --wildcard. It compiles, but leaves Rust symbols in libyjit.o.
+      - { uses: './.github/actions/compilers', name: 'clang 9',  with: { tag: 'clang-9',   append_configure: '--disable-yjit' } }
+      - { uses: './.github/actions/compilers', name: 'clang 8',  with: { tag: 'clang-8',   append_configure: '--disable-yjit' } }
+      - { uses: './.github/actions/compilers', name: 'clang 7',  with: { tag: 'clang-7',   append_configure: '--disable-yjit' } }
+      - { uses: './.github/actions/compilers', name: 'clang 6',  with: { tag: 'clang-6.0', append_configure: '--disable-yjit' } }
+      - { uses: './.github/actions/compilers', name: 'ext/Setup', with: { static_exts: 'etc json/* */escape' } }
+
+  compile5:
+    name: 'omnibus compilations, #5'
+    runs-on: ubuntu-latest
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Document')
+      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      )}}
+    services: { docuum: { image: 'stephanmisc/docuum', options: '--init', volumes: [ '/root', '/var/run/docker.sock:/var/run/docker.sock' ] } }
+    steps:
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true } }
+      # -Wno-strict-prototypes is necessary with current clang-15 since
+      # older autoconf generate functions without prototype and -pedantic
+      # now implies strict-prototypes. Disabling the error but leaving the
+      # warning generates a lot of noise from use of ANYARGS in
+      # rb_define_method() and friends.
+      # See: https://github.com/llvm/llvm-project/commit/11da1b53d8cd3507959022cd790d5a7ad4573d94
+      - { uses: './.github/actions/compilers', name: 'C99',   with: { CFLAGS:   '-std=c99   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
+      - { uses: './.github/actions/compilers', name: 'C11',   with: { CFLAGS:   '-std=c11   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
+      - { uses: './.github/actions/compilers', name: 'C17',   with: { CFLAGS:   '-std=c17   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
+      - { uses: './.github/actions/compilers', name: 'C23',   with: { CFLAGS:   '-std=c2x   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
+      - { uses: './.github/actions/compilers', name: 'C++98', with: { CXXFLAGS: '-std=c++98 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
+      - { uses: './.github/actions/compilers', name: 'C++11', with: { CXXFLAGS: '-std=c++11 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
+      - { uses: './.github/actions/compilers', name: 'C++14', with: { CXXFLAGS: '-std=c++14 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
+      - { uses: './.github/actions/compilers', name: 'C++17', with: { CXXFLAGS: '-std=c++17 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
+      - { uses: './.github/actions/compilers', name: 'C++20', with: { CXXFLAGS: '-std=c++20 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
+      - { uses: './.github/actions/compilers', name: 'C++23', with: { CXXFLAGS: '-std=c++23 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
+      - { uses: './.github/actions/compilers', name: 'C++26', with: { CXXFLAGS: '-std=c++26 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
+
+  compile6:
+    name: 'omnibus compilations, #6'
+    runs-on: ubuntu-latest
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Document')
+      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      )}}
+    services: { docuum: { image: 'stephanmisc/docuum', options: '--init', volumes: [ '/root', '/var/run/docker.sock:/var/run/docker.sock' ] } }
+    steps:
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true } }
+      - { uses: './.github/actions/compilers', name: '-O0', with: { optflags: '-O0 -march=x86-64 -mtune=generic' } }
+      - { uses: './.github/actions/compilers', name: '-O3', with: { optflags: '-O3 -march=x86-64 -mtune=generic', check: true } }
+      - { uses: './.github/actions/compilers', name: 'gmp',                 with: { append_configure: '--with-gmp', check: true } }
+      - { uses: './.github/actions/compilers', name: 'jemalloc',            with: { append_configure: '--with-jemalloc' } }
+      - { uses: './.github/actions/compilers', name: 'valgrind',            with: { append_configure: '--with-valgrind' } }
+      - { uses: './.github/actions/compilers', name: 'coroutine=ucontext',  with: { append_configure: '--with-coroutine=ucontext' } }
+      - { uses: './.github/actions/compilers', name: 'coroutine=pthread',   with: { append_configure: '--with-coroutine=pthread' } }
+
+  compile7:
+    name: 'omnibus compilations, #7'
+    runs-on: ubuntu-latest
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Document')
+      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      )}}
+    services: { docuum: { image: 'stephanmisc/docuum', options: '--init', volumes: [ '/root', '/var/run/docker.sock:/var/run/docker.sock' ] } }
+    steps:
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true } }
+      - { uses: './.github/actions/compilers', name: 'disable-jit',         with: { append_configure: '--disable-yjit --disable-rjit' } }
+      - { uses: './.github/actions/compilers', name: 'disable-dln',         with: { append_configure: '--disable-dln' } }
+      - { uses: './.github/actions/compilers', name: 'enable-mkmf-verbose', with: { append_configure: '--enable-mkmf-verbose' } }
+      - { uses: './.github/actions/compilers', name: 'disable-rubygems',    with: { append_configure: '--disable-rubygems' } }
+      - { uses: './.github/actions/compilers', name: 'RUBY_DEVEL',          with: { append_configure: '--enable-devel' } }
+      - { uses: './.github/actions/compilers', name: 'SHARED_GC',           with: { append_configure: '--with-shared-gc=/home/runner/shared-gc' } }
+      - { uses: './.github/actions/compilers', name: 'OPT_THREADED_CODE=0',            with: { cppflags: '-DOPT_THREADED_CODE=0' } }
+      - { uses: './.github/actions/compilers', name: 'OPT_THREADED_CODE=1',            with: { cppflags: '-DOPT_THREADED_CODE=1' } }
+      - { uses: './.github/actions/compilers', name: 'OPT_THREADED_CODE=2',            with: { cppflags: '-DOPT_THREADED_CODE=2' } }
+
+  compile8:
+    name: 'omnibus compilations, #8'
+    runs-on: ubuntu-latest
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Document')
+      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      )}}
+    services: { docuum: { image: 'stephanmisc/docuum', options: '--init', volumes: [ '/root', '/var/run/docker.sock:/var/run/docker.sock' ] } }
+    steps:
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true } }
+      - { uses: './.github/actions/compilers', name: 'NDEBUG',                         with: { cppflags: '-DNDEBUG' } }
+      - { uses: './.github/actions/compilers', name: 'RUBY_DEBUG',                     with: { cppflags: '-DRUBY_DEBUG' } }
+      - { uses: './.github/actions/compilers', name: 'ARRAY_DEBUG',                    with: { cppflags: '-DARRAY_DEBUG' } }
+      - { uses: './.github/actions/compilers', name: 'BIGNUM_DEBUG',                   with: { cppflags: '-DBIGNUM_DEBUG' } }
+      - { uses: './.github/actions/compilers', name: 'CCAN_LIST_DEBUG',                with: { cppflags: '-DCCAN_LIST_DEBUG' } }
+      - { uses: './.github/actions/compilers', name: 'CPDEBUG=-1',                     with: { cppflags: '-DCPDEBUG=-1' } }
+      - { uses: './.github/actions/compilers', name: 'ENC_DEBUG',                      with: { cppflags: '-DENC_DEBUG' } }
+      - { uses: './.github/actions/compilers', name: 'GC_DEBUG',                       with: { cppflags: '-DGC_DEBUG' } }
+      - { uses: './.github/actions/compilers', name: 'HASH_DEBUG',                     with: { cppflags: '-DHASH_DEBUG' } }
+      - { uses: './.github/actions/compilers', name: 'ID_TABLE_DEBUG',                 with: { cppflags: '-DID_TABLE_DEBUG' } }
+
+  compile9:
+    name: 'omnibus compilations, #9'
+    runs-on: ubuntu-latest
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Document')
+      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      )}}
+    services: { docuum: { image: 'stephanmisc/docuum', options: '--init', volumes: [ '/root', '/var/run/docker.sock:/var/run/docker.sock' ] } }
+    steps:
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true } }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_DEBUG=-1',                with: { cppflags: '-DRGENGC_DEBUG=-1' } }
+      - { uses: './.github/actions/compilers', name: 'SYMBOL_DEBUG',                   with: { cppflags: '-DSYMBOL_DEBUG' } }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_CHECK_MODE',              with: { cppflags: '-DRGENGC_CHECK_MODE' } }
+      - { uses: './.github/actions/compilers', name: 'VM_CHECK_MODE',                  with: { cppflags: '-DVM_CHECK_MODE' } }
+      - { uses: './.github/actions/compilers', name: 'USE_EMBED_CI=0',                 with: { cppflags: '-DUSE_EMBED_CI=0' } }
+      - { uses: './.github/actions/compilers', name: 'USE_FLONUM=0',                   with: { cppflags: '-DUSE_FLONUM=0', append_configure: '--disable-yjit' } }
+      - { uses: './.github/actions/compilers', name: 'USE_LAZY_LOAD',                  with: { cppflags: '-DUSE_LAZY_LOAD' } }
+      - { uses: './.github/actions/compilers', name: 'USE_SYMBOL_GC=0',                with: { cppflags: '-DUSE_SYMBOL_GC=0' } }
+      - { uses: './.github/actions/compilers', name: 'USE_THREAD_CACHE=0',             with: { cppflags: '-DUSE_THREAD_CACHE=0' } }
+
+  compileX:
+    name: 'omnibus compilations, #10'
+    runs-on: ubuntu-latest
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Document')
+      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      )}}
+    services: { docuum: { image: 'stephanmisc/docuum', options: '--init', volumes: [ '/root', '/var/run/docker.sock:/var/run/docker.sock' ] } }
+    steps:
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true } }
+      - { uses: './.github/actions/compilers', name: 'USE_RUBY_DEBUG_LOG=1',           with: { cppflags: '-DUSE_RUBY_DEBUG_LOG=1' } }
+      - { uses: './.github/actions/compilers', name: 'USE_DEBUG_COUNTER',              with: { cppflags: '-DUSE_DEBUG_COUNTER=1' } }
+      - { uses: './.github/actions/compilers', name: 'SHARABLE_MIDDLE_SUBSTRING',      with: { cppflags: '-DSHARABLE_MIDDLE_SUBSTRING=1' } }
+      - { uses: './.github/actions/compilers', name: 'DEBUG_FIND_TIME_NUMGUESS',       with: { cppflags: '-DDEBUG_FIND_TIME_NUMGUESS' } }
+      - { uses: './.github/actions/compilers', name: 'DEBUG_INTEGER_PACK',             with: { cppflags: '-DDEBUG_INTEGER_PACK' } }
+      - { uses: './.github/actions/compilers', name: 'ENABLE_PATH_CHECK',              with: { cppflags: '-DENABLE_PATH_CHECK' } }
+      - { uses: './.github/actions/compilers', name: 'GC_DEBUG_STRESS_TO_CLASS',       with: { cppflags: '-DGC_DEBUG_STRESS_TO_CLASS' } }
+      - { uses: './.github/actions/compilers', name: 'GC_ENABLE_LAZY_SWEEP=0',         with: { cppflags: '-DGC_ENABLE_LAZY_SWEEP=0' } }
+      - { uses: './.github/actions/compilers', name: 'GC_PROFILE_DETAIL_MEMORY',       with: { cppflags: '-DGC_PROFILE_DETAIL_MEMORY' } }
+
+  compileB:
+    name: 'omnibus compilations, #11'
+    runs-on: ubuntu-latest
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Document')
+      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      )}}
+    services: { docuum: { image: 'stephanmisc/docuum', options: '--init', volumes: [ '/root', '/var/run/docker.sock:/var/run/docker.sock' ] } }
+    steps:
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true } }
+      - { uses: './.github/actions/compilers', name: 'GC_PROFILE_MORE_DETAIL',         with: { cppflags: '-DGC_PROFILE_MORE_DETAIL' } }
+      - { uses: './.github/actions/compilers', name: 'MALLOC_ALLOCATED_SIZE_CHECK',    with: { cppflags: '-DMALLOC_ALLOCATED_SIZE_CHECK' } }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_ESTIMATE_OLDMALLOC',      with: { cppflags: '-DRGENGC_ESTIMATE_OLDMALLOC' } }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_FORCE_MAJOR_GC',          with: { cppflags: '-DRGENGC_FORCE_MAJOR_GC' } }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_OBJ_INFO',                with: { cppflags: '-DRGENGC_OBJ_INFO' } }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_PROFILE',                 with: { cppflags: '-DRGENGC_PROFILE' } }
+      - { uses: './.github/actions/compilers', name: 'VM_DEBUG_BP_CHECK',              with: { cppflags: '-DVM_DEBUG_BP_CHECK' } }
+      - { uses: './.github/actions/compilers', name: 'VM_DEBUG_VERIFY_METHOD_CACHE',   with: { cppflags: '-DVM_DEBUG_VERIFY_METHOD_CACHE' } }
+
+  compileC:
+    name: 'omnibus compilations, #12'
+    runs-on: ubuntu-latest
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Document')
+      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      )}}
+    services: { docuum: { image: 'stephanmisc/docuum', options: '--init', volumes: [ '/root', '/var/run/docker.sock:/var/run/docker.sock' ] } }
+    steps:
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true } }
+      - { uses: './.github/actions/compilers', name: 'enable-yjit',                    with: { append_configure: '--enable-yjit --disable-rjit' } }
+      - { uses: './.github/actions/compilers', name: 'enable-rjit',                    with: { append_configure: '--enable-rjit --disable-yjit' } }
+      - { uses: './.github/actions/compilers', name: 'YJIT_FORCE_ENABLE',              with: { cppflags: '-DYJIT_FORCE_ENABLE' } }
+      - { uses: './.github/actions/compilers', name: 'RJIT_FORCE_ENABLE',              with: { cppflags: '-DRJIT_FORCE_ENABLE' } }
+      - { uses: './.github/actions/compilers', name: 'UNIVERSAL_PARSER',               with: { cppflags: '-DUNIVERSAL_PARSER' } }
+
+  compilemax:
+    name: 'omnibus compilations, result'
+    runs-on: ubuntu-latest
+    if: ${{ always() }}
+    needs:
+      - 'compile1'
+      - 'compile2'
+      - 'compile3'
+      - 'compile4'
+      - 'compile5'
+      - 'compile6'
+      - 'compile7'
+      - 'compile8'
+      - 'compile9'
+      - 'compileX'
+      - 'compileB'
+      - 'compileC'
+    steps:
       - uses: ./.github/actions/slack
         with:
-          label: ${{ matrix.entry.name }}
+          label: 'omnibus'
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() }}
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+      - run: false
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
 
 defaults:
   run: