CI: also test clang and g++ compilers on Ubuntu

.github/workflows/CI.yml

@@ -37,10 +37,16 @@ jobs:
           else
             export CFLAGS="$CFLAGS -I../fortify-headers -D_FORTIFY_SOURCE=3 -DFORTIFY_PEDANTIC_CHECKS -O3"
           fi
+          if [[ "${{ matrix.os }}" == ubuntu-* ]]; then
+            make CHECK=1 CC=clang
+            make clean
+            make CHECK=1 CC=g++
+            make clean
+          fi
           make CHECK=1
           sudo ./tests/process_iterator_test
           random_file="$(mktemp $(printf 'X%.0s' $(seq 1 255)))"
-          cp ./tests/process_iterator_test ./tests/${random_file}
+          cp -f ./tests/process_iterator_test ./tests/${random_file}
           echo "./tests/${random_file}"
           sudo ./tests/${random_file}