Test clang rip builds on github to detect when it break.

Also adjust the normal rip build to use eatmydata when installing packages,
to speed up the test.

(cherry picked from commit f2b36d9)

Author: petterreinholdtsen

.github/workflows/ci.yml

@@ -26,17 +26,45 @@ jobs:
     - run: git fetch --recurse-submodules=no https://github.com/linuxcnc/linuxcnc refs/tags/*:refs/tags/*
     - name: Build RIP & test
       run: |
-        ./scripts/travis-install-build-deps.sh
+        set -x
         sudo apt-get install -y eatmydata
-        curl -O https://snapshot.debian.org/archive/debian/20220716T154603Z/pool/main/p/po4a/po4a_0.67-2_all.deb
-        sudo apt install ./po4a_0.67-2_all.deb
+        eatmydata ./scripts/travis-install-build-deps.sh
+        eatmydata curl -O https://snapshot.debian.org/archive/debian/20220716T154603Z/pool/main/p/po4a/po4a_0.67-2_all.deb
+        sudo eatmydata apt install ./po4a_0.67-2_all.deb
         cd src
         eatmydata ./autogen.sh
         eatmydata ./configure --with-realtime=uspace --disable-check-runtime-deps
         eatmydata make -O -j$((1+$(nproc))) default pycheck V=1
         # Note that the package build covers html docs
         eatmydata ../scripts/rip-environment runtests -p
 
+  rip-and-test-clang:
+    runs-on: ubuntu-20.04
+    steps:
+    - name: Dump GitHub context
+      env:
+        GITHUB_CONTEXT: ${{ toJson(github) }}
+      run: echo "$GITHUB_CONTEXT"
+    - uses: actions/checkout@v2
+      with:
+        submodules: true
+        fetch-depth: 0
+    - run: git fetch --recurse-submodules=no https://github.com/linuxcnc/linuxcnc refs/tags/*:refs/tags/*
+    - name: Clang build RIP & test
+      run: |
+        set -x
+        sudo apt-get install -y eatmydata
+        eatmydata ./scripts/travis-install-build-deps.sh
+        sudo eatmydata apt-get install -y clang
+        eatmydata curl -O https://snapshot.debian.org/archive/debian/20220716T154603Z/pool/main/p/po4a/po4a_0.67-2_all.deb
+        sudo eatmydata apt install ./po4a_0.67-2_all.deb
+        cd src
+        eatmydata ./autogen.sh
+        CC=clang CXX=clang++ eatmydata ./configure --with-realtime=uspace --disable-check-runtime-deps
+        eatmydata make -O -j$((1+$(nproc))) default pycheck V=1
+        # Note that the package build covers html docs
+        eatmydata ../scripts/rip-environment runtests -p
+
   htmldocs:
     runs-on: ubuntu-20.04
     steps: