diff --git a/.github/workflows/ccpp.yml b/.github/workflows/ccpp.yml
index 2d0570878..2fe6c326c 100644
--- a/.github/workflows/ccpp.yml
+++ b/.github/workflows/ccpp.yml
@@ -8,7 +8,7 @@ on:
         branches:
             - main
 jobs:
-  build:
+  build-autotools-gcc:
     runs-on: ubuntu-latest
     container:
       image: fvwmorg/fvwm3-build:latest
@@ -24,7 +24,7 @@ jobs:
       - name: Autotools build
         run: make -j
 
-  build-meson:
+  build-meson-clang:
     runs-on: ubuntu-latest
     container: fvwmorg/fvwm3-build:latest
     steps:
@@ -37,6 +37,66 @@ jobs:
       - name: run build
         run: ninja -C builddir
 
+  build-meson-gcc-lto:
+    runs-on: ubuntu-latest
+    container: fvwmorg/fvwm3-build:latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+      - name: set git safe directory
+        run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
+      - name: configure meson build
+        run: CFLAGS="-flto -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing" meson setup builddir -Dhtmldoc=true -Dmandoc=true -Dxent=true -Drsvg=true -Dpng=true -Dauto_features=enabled
+      - name: run build
+        run: ninja -C builddir
+
+  build-gentoo-gcc:
+    runs-on: ubuntu-latest
+    container:
+        image: gentoo/stage3:nomultilib
+    steps:
+    - name: Install dependencies
+      run: >
+        emerge-webrsync && getuto &&
+        echo "x11-wm/fvwm3" > /etc/portage/package.accept_keywords/foo &&
+        echo "dev-build/meson" > /etc/portage/package.accept_keywords/meson &&
+        echo "dev-python/pillow truetype" > /etc/portage/package.use/pillow &&
+        USE="-harfbuzz" emerge media-libs/freetype &&
+        emerge --autounmask-continue --getbinpkg --onlydeps x11-wm/fvwm3 &&
+        emerge --getbinpkg dev-vcs/git dev-build/meson
+    - name: Check out repository code
+      uses: actions/checkout@v4
+    - name: set git safe directory
+      run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
+    - name: configure meson build
+      run:  meson setup builddir
+    - name: run build
+      run: ninja -C builddir
+
+  build-gentoo-clang:
+    runs-on: ubuntu-latest
+    container:
+        image: gentoo/stage3:nomultilib
+    steps:
+        - name: Install dependencies
+          run: >
+            emerge-webrsync && getuto &&
+            echo "x11-wm/fvwm3" > /etc/portage/package.accept_keywords/foo &&
+            echo "dev-build/meson" > /etc/portage/package.accept_keywords/meson &&
+            echo "dev-python/pillow truetype" > /etc/portage/package.use/pillow &&
+            USE="-harfbuzz" emerge media-libs/freetype &&
+            emerge --autounmask-continue --getbinpkg --onlydeps x11-wm/fvwm3 &&
+            emerge --getbinpkg sys-devel/clang sys-devel/lld dev-build/meson dev-vcs/git &&
+            env-update
+        - name: Check out repository code
+          uses: actions/checkout@v4
+        - name: set git safe directory
+          run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
+        - name: configure meson build
+          run: . /etc/profile && CC=clang CC_LD=lld meson setup builddir
+        - name: run build
+          run: . /etc/profile && ninja -C builddir
+
   notification:
     runs-on: ubuntu-20.04
     name: notifications
@@ -45,7 +105,7 @@ jobs:
         uses: Gottox/irc-message-action@v2.1.3
         if: github.event_name == 'pull_request'
         with:
-          server: "irc.libera.chat"
+          server: irc.libera.chat
           notice: false
           channel: "#fvwm"
           nickname: fvwm3-gh-pr
@@ -54,7 +114,7 @@ jobs:
         uses: Gottox/irc-message-action@v2.1.3
         if: github.event_name == 'create' && github.event.ref_type == 'tag'
         with:
-          server: "irc.libera.chat"
+          server: irc.libera.chat
           notice: false
           channel: "#fvwm"
           nickname: fvwm-gh