diff --git a/.github/actions/cmake_config/Dockerfile b/.github/actions/cmake_config/Dockerfile
deleted file mode 100644
index 63b28a99..00000000
--- a/.github/actions/cmake_config/Dockerfile
+++ /dev/null
@@ -1,16 +0,0 @@
-FROM ubuntu:18.04
-
-RUN apt-get update \
- && apt-get install -y --no-install-recommends \
-        g++=4:7.4.0-1ubuntu2.3 \
-        wget=1.19.4-1ubuntu2.2 \
-        libidn11=1.33-2.1ubuntu1.2 \
-        ca-certificates=20180409 \
-        make=4.1-9.1ubuntu1 \
-        git=1:2.17.1-1ubuntu0.7 \
- && apt-get clean \
- && rm -rf /var/lib/apt/lists/*
-
-COPY entrypoint.sh /entrypoint.sh
-
-ENTRYPOINT ["/entrypoint.sh"]
diff --git a/.github/actions/cmake_config/action.yml b/.github/actions/cmake_config/action.yml
deleted file mode 100644
index 73ff1661..00000000
--- a/.github/actions/cmake_config/action.yml
+++ /dev/null
@@ -1,16 +0,0 @@
-description: 'Test out a bare bones configuration with a CMake version'
-inputs:
-  version:
-    description: 'The full version of CMake to check'
-    required: true
-  options:
-    description: 'The CMake configuration options'
-    required: false
-    default: ""
-name: 'Configure with CMake'
-runs:
-  using: 'docker'
-  image: 'Dockerfile'
-  args:
-    - ${{ inputs.version }}
-    - ${{ inputs.options }}
diff --git a/.github/actions/cmake_config/entrypoint.sh b/.github/actions/cmake_config/entrypoint.sh
deleted file mode 100755
index e3bd622e..00000000
--- a/.github/actions/cmake_config/entrypoint.sh
+++ /dev/null
@@ -1,23 +0,0 @@
-#!/bin/bash -l
-
-set -ex
-
-mkdir -p cmake_dir
-mkdir -p build_tmp
-mkdir -p cmake_sources
-rm -rf cmake_dir/* build_tmp/*
-
-v=$1
-fn=cmake-$v-Linux-x86_64.tar.gz
-
-if [ ! -f cmake_sources/$fn ]; then
-    wget -qO cmake_sources/$fn "https://cmake.org/files/v${v%.*}/$fn"
-fi
-
-tar -xzf cmake_sources/$fn --strip-components=1 -C $PWD/cmake_dir
-
-export PATH=$PWD/cmake_dir/bin:$PATH
-
-cmake --version
-
-cd build_tmp && cmake .. $2
diff --git a/.github/actions/quick_cmake/action.yml b/.github/actions/quick_cmake/action.yml
new file mode 100644
index 00000000..da721a78
--- /dev/null
+++ b/.github/actions/quick_cmake/action.yml
@@ -0,0 +1,18 @@
+name: Quick CMake config
+description: 'Runs CMake 3.4+ (if already setup)'
+inputs:
+  args:
+    description: 'Other arguments'
+    required: false
+    default: ''
+
+runs:
+  using: composite
+  steps:
+    - run: |
+        mkdir -p build-tmp
+        touch build-tmp/tmp
+        rm -r build-tmp/*
+        (cd build-tmp && cmake .. ${{ inputs.args}})
+        rm -r build-tmp
+      shell: bash
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 36777042..7639c0c9 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -39,81 +39,144 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-      with:
-        submodules: true
+
     - name: CMake 3.4
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.4.3
+        cmake-version: "3.4"
+    - name: Check CMake 3.4
+      uses: ./.github/actions/quick_cmake
+
     - name: CMake 3.5
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.5.2
+        cmake-version: "3.5"
+    - name: Check CMake 3.5
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
+
     - name: CMake 3.6
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.6.3
+        cmake-version: "3.6"
+    - name: Check CMake 3.6
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
+
     - name: CMake 3.7
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.7.2
+        cmake-version: "3.7"
+    - name: Check CMake 3.7
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
+
     - name: CMake 3.8
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.8.2
+        cmake-version: "3.8"
+    - name: Check CMake 3.8
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
+
     - name: CMake 3.9
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.9.6
+        cmake-version: "3.9"
+    - name: Check CMake 3.9
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
+
     - name: CMake 3.10
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.10.3
+        cmake-version: "3.10"
+    - name: Check CMake 3.10
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
-    - name: CMake 3.11 (full)
-      uses: ./.github/actions/cmake_config
+
+    - name: CMake 3.11
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.11.4
-        options: -DCLI11_SANITIZERS=ON -DCLI11_BUILD_EXAMPLES_JSON=ON
+        cmake-version: "3.11"
+    - name: Check CMake 3.11 (full)
+      uses: ./.github/actions/quick_cmake
+      with:
+        args: -DCLI11_SANITIZERS=ON -DCLI11_BUILD_EXAMPLES_JSON=ON
       if: success() || failure()
+
     - name: CMake 3.12
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.12.4
+        cmake-version: "3.12"
+    - name: Check CMake 3.12
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
+
     - name: CMake 3.13
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.13.5
+        cmake-version: "3.13"
+    - name: Check CMake 3.13
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
+
     - name: CMake 3.14
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.14.7
+        cmake-version: "3.14"
+    - name: Check CMake 3.14
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
+
     - name: CMake 3.15
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.15.6
+        cmake-version: "3.15"
+    - name: Check CMake 3.15
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
+
     - name: CMake 3.16
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.16.8
+        cmake-version: "3.16"
+    - name: Check CMake 3.16
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
+
     - name: CMake 3.17
-      uses: ./.github/actions/cmake_config
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.17.3
+        cmake-version: "3.17"
+    - name: Check CMake 3.17
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
-    - name: CMake 3.18 (full)
-      uses: ./.github/actions/cmake_config
+
+    - name: CMake 3.18
+      uses: jwlawson/actions-setup-cmake@v1.8
       with:
-        version: 3.18.0
-        options: -DCLI11_SANITIZERS=ON -DCLI11_BUILD_EXAMPLES_JSON=ON
+        cmake-version: "3.18"
+    - name: Check CMake 3.18
+      uses: ./.github/actions/quick_cmake
       if: success() || failure()
+
+    - name: CMake 3.19
+      uses: jwlawson/actions-setup-cmake@v1.8
+      with:
+        cmake-version: "3.19"
+    - name: Check CMake 3.19 (full)
+      uses: ./.github/actions/quick_cmake
+      with:
+        args: -DCLI11_SANITIZERS=ON -DCLI11_BUILD_EXAMPLES_JSON=ON
+      if: success() || failure()
+
+    - name: CMake 3.20
+      uses: jwlawson/actions-setup-cmake@v1.8
+      with:
+        cmake-version: "3.20"
+    - name: Check CMake 3.20
+      uses: ./.github/actions/quick_cmake
+      if: success() || failure()
+
+