diff --git a/.github/actions/setup-build-env/action.yml b/.github/actions/setup-build-env/action.yml
index c1d3e2b01..b61bb95ac 100644
--- a/.github/actions/setup-build-env/action.yml
+++ b/.github/actions/setup-build-env/action.yml
@@ -33,21 +33,21 @@ runs:
     # and docs/source/getting_started/installation.rst to match.
     - name: Linux common dependencies
       if: runner.os == 'Linux'
-      uses: awalsh128/cache-apt-pkgs-action@v1.6.0
+      uses: awalsh128/cache-apt-pkgs-action@v1.6.1
       with:
         packages: gawk git make python3
         version: ${{ inputs.runs-on }}-commonys
 
     - name: Linux build dependencies
       if: runner.os == 'Linux' && inputs.get-build-deps == 'true'
-      uses: awalsh128/cache-apt-pkgs-action@v1.6.0
+      uses: awalsh128/cache-apt-pkgs-action@v1.6.1
       with:
         packages: bison clang flex libffi-dev libfl-dev libreadline-dev pkg-config tcl-dev zlib1g-dev libgtest-dev libgmock-dev
         version: ${{ inputs.runs-on }}-buildys
 
     - name: Linux docs dependencies
       if: runner.os == 'Linux' && inputs.get-docs-deps == 'true'
-      uses: awalsh128/cache-apt-pkgs-action@v1.6.0
+      uses: awalsh128/cache-apt-pkgs-action@v1.6.1
       with:
         packages: graphviz xdot
         version: ${{ inputs.runs-on }}-docsys
@@ -70,7 +70,7 @@ runs:
       shell: bash
       run: |
         echo "${{ github.workspace }}/.local/bin" >> $GITHUB_PATH
-        echo "$(brew --prefix llvm@20)/bin" >> $GITHUB_PATH
+        echo "$(brew --prefix llvm)/bin" >> $GITHUB_PATH
         echo "$(brew --prefix bison)/bin" >> $GITHUB_PATH
         echo "$(brew --prefix flex)/bin" >> $GITHUB_PATH
         echo "procs=$(sysctl -n hw.ncpu)" >> $GITHUB_ENV
diff --git a/.github/actions/setup-iverilog/action.yml b/.github/actions/setup-iverilog/action.yml
index 0acb582e3..3457303e2 100644
--- a/.github/actions/setup-iverilog/action.yml
+++ b/.github/actions/setup-iverilog/action.yml
@@ -11,7 +11,7 @@ runs:
   steps:
     - name: iverilog Linux deps
       if: steps.restore-iverilog.outputs.cache-hit != 'true' && runner.os == 'Linux'
-      uses: awalsh128/cache-apt-pkgs-action@v1.6.0
+      uses: awalsh128/cache-apt-pkgs-action@v1.6.1
       with:
         packages: autoconf gperf make gcc g++ bison flex libbz2-dev
         version: ${{ inputs.runs-on }}-iverilog
@@ -40,7 +40,7 @@ runs:
         make -j$procs
         make install
 
-    - uses: actions/cache/restore@v4
+    - uses: actions/cache/restore@v6
       id: restore-iverilog
       with:
         path: .local/
@@ -62,7 +62,7 @@ runs:
       run: |
         iverilog -V
 
-    - uses: actions/cache/save@v4
+    - uses: actions/cache/save@v6
       id: save-iverilog
       if: steps.restore-iverilog.outputs.cache-hit != 'true'
       with:
diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index dcdfc03cb..708f6e4ac 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -3,7 +3,7 @@ name: "CodeQL"
 on:
   workflow_dispatch:
   schedule:
-    - cron: '0 3 * * *'
+    - cron: '0 3 * * 6'
 
 jobs:
   analyze:
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v5
+      uses: actions/checkout@v7
       with:
         submodules: true
         persist-credentials: false
diff --git a/.github/workflows/extra-builds.yml b/.github/workflows/extra-builds.yml
index 603d91e5d..411fd9f55 100644
--- a/.github/workflows/extra-builds.yml
+++ b/.github/workflows/extra-builds.yml
@@ -15,7 +15,7 @@ jobs:
     steps:
       - id: skip_check
         if: ${{ github.event_name != 'merge_group' }}
-        uses: fkirc/skip-duplicate-actions@v5
+        uses: mmicko/skip-duplicate-actions@master
         with:
           # don't run on documentation changes
           paths_ignore: '["**/README.md", "docs/**", "guidelines/**"]'
@@ -37,13 +37,22 @@ jobs:
     needs: [pre_job]
     if: (github.event_name == 'merge_group' || github.event_name == 'workflow_dispatch') && needs.pre_job.outputs.should_skip != 'true'
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
         with:
           submodules: true
           persist-credentials: false
 
       - name: Setup MSVC
-        uses: ilammy/msvc-dev-cmd@v1
+        uses: TheMrMilchmann/setup-msvc-dev@v4
+        with:
+          arch: x64
+
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@v1.2.23
+        with:
+          key: vs-build
+          restore-keys: |
+            vs-build-
 
       - name: Install flex/bison
         shell: pwsh
@@ -57,8 +66,9 @@ jobs:
       - name: Configure CMake
         run: >
           cmake -S . -B build
-          -A x64
+          -G Ninja
           -DCMAKE_BUILD_TYPE=Release
+          -DYOSYS_COMPILER_LAUNCHER=ccache
 
       - name: Build
         run: >
@@ -72,7 +82,7 @@ jobs:
     needs: [pre_job]
     if: (github.event_name == 'merge_group' || github.event_name == 'workflow_dispatch') && needs.pre_job.outputs.should_skip != 'true'
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
         with:
           submodules: true
           persist-credentials: false
@@ -85,6 +95,11 @@ jobs:
 
           install: >-
             base-devel
+            bison
+            flex
+            gawk
+            diffutils
+            make
             mingw-w64-x86_64-toolchain
             mingw-w64-x86_64-cmake
             mingw-w64-x86_64-gtest
@@ -93,13 +108,14 @@ jobs:
             mingw-w64-x86_64-tcl
             mingw-w64-x86_64-libffi
             mingw-w64-x86_64-git
+            mingw-w64-x86_64-ccache
 
-          msys2-install: >-
-            bison
-            flex
-            gawk
-            diffutils
-            make
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@v1.2.23
+        with:
+          key: mingw-build
+          restore-keys: |
+            mingw-build-
 
       - name: Build Yosys
         shell: msys2 {0}
@@ -107,7 +123,7 @@ jobs:
           set -e
           procs=$(nproc)
           rm -rf build
-          cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
+          cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DYOSYS_COMPILER_LAUNCHER=ccache
           cmake --build build -j${procs}
           ctest --test-dir build/tests/unit --output-on-failure
 
@@ -117,10 +133,18 @@ jobs:
     if: (github.event_name == 'merge_group' || github.event_name == 'workflow_dispatch') && needs.pre_job.outputs.should_skip != 'true'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
         with:
           submodules: true
           persist-credentials: false
+
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@v1.2.23
+        with:
+          key: wasi-build
+          restore-keys: |
+            wasi-build-
+
       - name: Build
         run: |
           WASI_VER=33
@@ -140,7 +164,7 @@ jobs:
             make install)
 
           export PATH=${WASI_SDK_PATH}/bin:$(pwd)/flex-prefix/bin:${PATH}
-          cmake -B build -DCMAKE_TOOLCHAIN_FILE=${WASI_SDK_PATH}/share/cmake/wasi-sdk-p1.cmake -DCMAKE_BUILD_TYPE=Release .
+          cmake -B build -DCMAKE_TOOLCHAIN_FILE=${WASI_SDK_PATH}/share/cmake/wasi-sdk-p1.cmake -DCMAKE_BUILD_TYPE=Release -DYOSYS_COMPILER_LAUNCHER=ccache .
           cmake --build build -j$(nproc)
 
   nix-build:
@@ -153,7 +177,7 @@ jobs:
         os: [ubuntu-latest, macos-latest]
       fail-fast: false
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
         with:
           submodules: true
           persist-credentials: false
diff --git a/.github/workflows/prepare-docs.yml b/.github/workflows/prepare-docs.yml
index ff2b96872..32f4619f7 100644
--- a/.github/workflows/prepare-docs.yml
+++ b/.github/workflows/prepare-docs.yml
@@ -18,7 +18,7 @@ jobs:
       docs_export: ${{ github.ref == 'refs/heads/main' || startsWith(github.ref, 'refs/heads/docs-preview') || startsWith(github.ref, 'refs/tags/') }}
     steps:
       - id: skip_check
-        uses: fkirc/skip-duplicate-actions@v5
+        uses: mmicko/skip-duplicate-actions@master
         with:
           paths_ignore: '["**/README.md"]'
           # don't cancel in case we're updating docs
@@ -46,7 +46,7 @@ jobs:
     runs-on: [self-hosted, linux, x64, fast]
     steps:
       - name: Checkout Yosys
-        uses: actions/checkout@v4
+        uses: actions/checkout@v7
         with:
           persist-credentials: false
           submodules: true
@@ -72,7 +72,7 @@ jobs:
           cmake --build build --target docs-prepare -j$procs
 
       - name: Upload artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: cmd-ref-${{ github.sha }}
           path: |
diff --git a/.github/workflows/source-vendor.yml b/.github/workflows/source-vendor.yml
index d85b2af08..b64306c29 100644
--- a/.github/workflows/source-vendor.yml
+++ b/.github/workflows/source-vendor.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository with submodules
-        uses: actions/checkout@v5
+        uses: actions/checkout@v7
         with:
           submodules: 'recursive'
           persist-credentials: false
diff --git a/.github/workflows/test-build.yml b/.github/workflows/test-build.yml
index e09fd9eb3..0c8ac6b90 100644
--- a/.github/workflows/test-build.yml
+++ b/.github/workflows/test-build.yml
@@ -15,7 +15,7 @@ jobs:
     steps:
       - id: skip_check
         if: ${{ github.event_name != 'merge_group' }}
-        uses: fkirc/skip-duplicate-actions@v5
+        uses: mmicko/skip-duplicate-actions@master
         with:
           # don't run on documentation changes
           paths_ignore: '["**/README.md", "docs/**", "guidelines/**"]'
@@ -38,7 +38,7 @@ jobs:
     steps:
       - id: skip_check
         if: ${{ github.event_name != 'merge_group' }}
-        uses: fkirc/skip-duplicate-actions@v5
+        uses: mmicko/skip-duplicate-actions@master
         with:
           # don't run on readme changes
           paths_ignore: '["**/README.md"]'
@@ -68,7 +68,7 @@ jobs:
       fail-fast: false
     steps:
       - name: Checkout Yosys
-        uses: actions/checkout@v5
+        uses: actions/checkout@v7
         with:
           submodules: true
           persist-credentials: false
@@ -79,11 +79,18 @@ jobs:
           runs-on: ${{ matrix.os }}
           get-build-deps: true
 
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@v1.2.23
+        with:
+          key: test-build-${{ matrix.os }}
+          restore-keys: |
+            test-build-${{ matrix.os }}-
+
       - name: Build
         shell: bash
         run: |
           rm -rf build
-          cmake -B build . -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=Release
+          cmake -B build . -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=Release -DYOSYS_COMPILER_LAUNCHER=ccache
           cmake --build build -j$procs
           ctest --test-dir build/tests/unit
 
@@ -117,7 +124,7 @@ jobs:
       fail-fast: false
     steps:
       - name: Checkout Yosys
-        uses: actions/checkout@v5
+        uses: actions/checkout@v7
         with:
           persist-credentials: false
 
@@ -166,7 +173,7 @@ jobs:
         os: [ubuntu-latest]
     steps:
       - name: Checkout Yosys
-        uses: actions/checkout@v5
+        uses: actions/checkout@v7
         with:
           persist-credentials: false
 
@@ -204,7 +211,7 @@ jobs:
       fail-fast: false
     steps:
       - name: Checkout Yosys
-        uses: actions/checkout@v5
+        uses: actions/checkout@v7
         with:
           persist-credentials: false
 
@@ -246,7 +253,7 @@ jobs:
       fail-fast: false
     steps:
       - name: Checkout Yosys
-        uses: actions/checkout@v4
+        uses: actions/checkout@v7
         with:
           submodules: true
           persist-credentials: false
@@ -276,7 +283,7 @@ jobs:
           cmake --build build --target docs-${{ matrix.docs-target }} -j$procs
 
       - name: Store docs build artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: docs-build-${{ matrix.docs-target }}
           path: docs/build/
diff --git a/.github/workflows/test-compile.yml b/.github/workflows/test-compile.yml
index 3093e8dfd..fafa82894 100644
--- a/.github/workflows/test-compile.yml
+++ b/.github/workflows/test-compile.yml
@@ -15,7 +15,7 @@ jobs:
     steps:
       - id: skip_check
         if: ${{ github.event_name != 'merge_group' }}
-        uses: fkirc/skip-duplicate-actions@v5
+        uses: mmicko/skip-duplicate-actions@master
         with:
           # don't run on documentation changes
           paths_ignore: '["**/README.md", "docs/**", "guidelines/**"]'
@@ -49,16 +49,13 @@ jobs:
           - 'clang-22'
           - 'gcc-16'
         include:
-          # macOS x86
-          - os: macos-15-intel
-            compiler: 'clang-22'
           # macOS arm
           - os: macos-latest
             compiler: 'clang-22'
       fail-fast: false
     steps:
       - name: Checkout Yosys
-        uses: actions/checkout@v5
+        uses: actions/checkout@v7
         with:
           submodules: true
           persist-credentials: false
@@ -69,6 +66,13 @@ jobs:
           runs-on: ${{ matrix.os }}
           get-build-deps: true
 
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@v1.2.23
+        with:
+          key: test-compile-${{ matrix.os }}-${{ matrix.compiler }}
+          restore-keys: |
+            test-compile-${{ matrix.os }}-${{ matrix.compiler }}-
+
       - name: Setup Cpp
         uses: aminya/setup-cpp@v1
         with:
@@ -91,7 +95,7 @@ jobs:
         shell: bash
         run: |
           rm -rf build
-          cmake -B build -DCMAKE_CXX_STANDARD=20 . --fresh
+          cmake -B build -DCMAKE_CXX_STANDARD=20 -DYOSYS_COMPILER_LAUNCHER=ccache . --fresh
           cmake --build build --target yosys -j$procs
 
       # maximum standard, only on newest compilers
@@ -100,7 +104,7 @@ jobs:
         shell: bash
         run: |
           rm -rf build
-          cmake -B build -DCMAKE_CXX_STANDARD=26 . --fresh
+          cmake -B build -DCMAKE_CXX_STANDARD=26 -DYOSYS_COMPILER_LAUNCHER=ccache . --fresh
           cmake --build build --target yosys -j$procs
 
   test-compile-result:
diff --git a/.github/workflows/test-sanitizers.yml b/.github/workflows/test-sanitizers.yml
index d6c77fcf1..5439b16b4 100644
--- a/.github/workflows/test-sanitizers.yml
+++ b/.github/workflows/test-sanitizers.yml
@@ -15,7 +15,7 @@ jobs:
     steps:
       - id: skip_check
         if: ${{ github.event_name != 'merge_group' }}
-        uses: fkirc/skip-duplicate-actions@v5
+        uses: mmicko/skip-duplicate-actions@master
         with:
           # don't run on documentation changes
           paths_ignore: '["**/README.md", "docs/**", "guidelines/**"]'
@@ -47,7 +47,7 @@ jobs:
       fail-fast: false
     steps:
       - name: Checkout Yosys
-        uses: actions/checkout@v5
+        uses: actions/checkout@v7
         with:
           submodules: true
           persist-credentials: false
@@ -60,13 +60,21 @@ jobs:
           get-test-deps: true
           get-iverilog: true
 
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@v1.2.23
+        with:
+          key: test-san-${{ matrix.os }}
+          restore-keys: |
+            test-san-${{ matrix.os }}-
+
       - name: Build
         shell: bash
         run: |
           rm -rf build
           cmake -B build . \
                 -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ \
-                -DCMAKE_BUILD_TYPE=Sanitize -DSANITIZE=${{ matrix.sanitizer }}
+                -DCMAKE_BUILD_TYPE=Sanitize -DSANITIZE=${{ matrix.sanitizer }} \
+                -DYOSYS_COMPILER_LAUNCHER=ccache
           cmake --build build -j$procs
 
       - name: Log yosys-config output
diff --git a/.github/workflows/test-verific-cfg.yml b/.github/workflows/test-verific-cfg.yml
index 6721c0c9b..733eb2989 100644
--- a/.github/workflows/test-verific-cfg.yml
+++ b/.github/workflows/test-verific-cfg.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: [self-hosted, linux, x64, fast]
     steps:
       - name: Checkout Yosys
-        uses: actions/checkout@v4
+        uses: actions/checkout@v7
         with:
           persist-credentials: false
           submodules: true
diff --git a/.github/workflows/test-verific.yml b/.github/workflows/test-verific.yml
index 9143c2f19..f268f4b65 100644
--- a/.github/workflows/test-verific.yml
+++ b/.github/workflows/test-verific.yml
@@ -15,7 +15,7 @@ jobs:
     steps:
       - id: skip_check
         if: ${{ github.event_name != 'merge_group' }}
-        uses: fkirc/skip-duplicate-actions@v5
+        uses: mmicko/skip-duplicate-actions@master
         with:
           # don't run on documentation changes
           paths_ignore: '["**/README.md", "docs/**", "guidelines/**"]'
@@ -37,7 +37,7 @@ jobs:
     runs-on: [self-hosted, linux, x64, fast]
     steps:
       - name: Checkout Yosys
-        uses: actions/checkout@v4
+        uses: actions/checkout@v7
         with:
           persist-credentials: false
           submodules: true
@@ -70,7 +70,7 @@ jobs:
           cmake --build build --target install
 
       - name: Checkout SBY
-        uses: actions/checkout@v4
+        uses: actions/checkout@v7
         with:
           repository: 'YosysHQ/sby'
           path: 'sby'
@@ -125,7 +125,7 @@ jobs:
     runs-on: [self-hosted, linux, x64, fast]
     steps:
       - name: Checkout Yosys
-        uses: actions/checkout@v4
+        uses: actions/checkout@v7
         with:
           persist-credentials: false
           submodules: true
diff --git a/.github/workflows/wheels.yml b/.github/workflows/wheels.yml
index e6381a637..043c9a664 100644
--- a/.github/workflows/wheels.yml
+++ b/.github/workflows/wheels.yml
@@ -47,7 +47,7 @@ jobs:
     name: Build Wheels | ${{ matrix.os.name }} | ${{ matrix.os.archs }}
     runs-on: ${{ matrix.os.runner }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
         with:
           fetch-depth: 0
           submodules: true