package/archlinux: enable colored output in dev PKGBUILDs.

package/archlinux/PKGBUILD

@@ -20,12 +20,19 @@ build() {
     mkdir -p "$_rootdir/build"
     cd "$_rootdir/build"
 
-    # Only one of these is built
+    # Only one of these is built.
+    #
+    # Colored output is enabled implicitly. If Ninja detects it's outputting to
+    # a pipe, it strips it away from the output, alternatively you can set the
+    # GCC_COLORS= (empty) env variable to temporarily disable colors. The
+    # inverse, i.e. preserving colors when Ninja outputs to a pipe can be done
+    # with CLICOLOR_FORCE=1: https://github.com/ninja-build/ninja/issues/2196
     cmake .. \
         -DCMAKE_CONFIGURATION_TYPES="Release;Debug;RelWithDebInfo" \
         -DCMAKE_CROSS_CONFIGS=all \
         -DCMAKE_CXX_FLAGS_RELWITHDEBINFO="-O2 -g -DNDEBUG -fno-omit-frame-pointer" \
         -DCMAKE_INSTALL_PREFIX=/usr \
+        -DCMAKE_COLOR_DIAGNOSTICS=ON \
         -DMAGNUM_WITH_PYTHON=ON \
         -DMAGNUM_BUILD_TESTS=ON \
         -G "Ninja Multi-Config"

package/archlinux/PKGBUILD-coverage

@@ -20,10 +20,16 @@ build() {
     newcxxflags=$(echo $CXXFLAGS | sed s/-O.//g | sed s/-D_FORTIFY_SOURCE=.//g)
     export CXXFLAGS="$newcxxflags"
 
+    # Colored output is enabled implicitly. If Ninja detects it's outputting to
+    # a pipe, it strips it away from the output, alternatively you can set the
+    # GCC_COLORS= (empty) env variable to temporarily disable colors. The
+    # inverse, i.e. preserving colors when Ninja outputs to a pipe can be done
+    # with CLICOLOR_FORCE=1: https://github.com/ninja-build/ninja/issues/2196
     cmake .. \
         -DCMAKE_CXX_FLAGS="--coverage" \
         -DCMAKE_BUILD_TYPE=Debug \
         -DCMAKE_INSTALL_PREFIX=/usr \
+        -DCMAKE_COLOR_DIAGNOSTICS=ON \
         -DMAGNUM_WITH_PYTHON=ON \
         -DMAGNUM_BUILD_TESTS=ON \
         -G Ninja