Auto-detect level of parallelism

.gitlab-ci.yml

@@ -20,11 +20,7 @@ variables:
    - DEBIAN_FRONTEND=noninteractive apt-get -y install build-essential git cmake libpng-dev libjpeg-dev libxxf86vm-dev libgl1-mesa-dev libsqlite3-dev libleveldb-dev libogg-dev libvorbis-dev libopenal-dev libcurl4-gnutls-dev libfreetype6-dev zlib1g-dev libgmp-dev libjsoncpp-dev libzstd-dev
   script:
     - git clone https://github.com/minetest/irrlicht -b $IRRLICHT_TAG lib/irrlichtmt
-    - mkdir build
-    - cd build
-    - cmake -DCMAKE_INSTALL_PREFIX=../artifact/minetest/usr/ -DCMAKE_BUILD_TYPE=Release -DRUN_IN_PLACE=FALSE -DENABLE_GETTEXT=TRUE -DBUILD_SERVER=TRUE ..
-    - make -j2
-    - make install
+    - make -j$(($(nproc) + 1))
   artifacts:
     when: on_success
     expire_in: 1h

util/ci/build.sh

@@ -5,4 +5,4 @@ cd build
 cmake -DCMAKE_BUILD_TYPE=Debug \
 	-DRUN_IN_PLACE=TRUE -DENABLE_GETTEXT=TRUE \
 	-DBUILD_SERVER=TRUE ${CMAKE_FLAGS} ..
-make -j2
+make -j$(($(nproc) + 1))

util/ci/build_prometheus_cpp.sh

@@ -8,6 +8,6 @@ cmake .. \
 	-DCMAKE_INSTALL_PREFIX=/usr/local \
 	-DCMAKE_BUILD_TYPE=Release \
 	-DENABLE_TESTING=0
-make -j2
+make -j$(nproc)
 sudo make install