ci: speed up build by parallelizing debuild and cleaning up apt steps

- Remove unnecessary meson PPA (Ubuntu 22.04 ships meson 0.61.2, requirement is >=0.53.0)
- Add apt package cache (actions/cache@v4) to skip downloads on repeat runs
- Drop pointless apt cleanup at end of install step (runner is ephemeral)
- Parallelize all debian/rules for-loops (configure, install, makeshlibs, shlibdeps)
  using xargs -P$(nproc) to run all ~61 targets concurrently instead of serially

Author: HeyMeco

.github/workflows/build.yml

@@ -34,11 +34,15 @@ jobs:
           mkdir -p ~/.config/git
           chmod -R 700 ~/.config
 
+      - name: Cache apt packages
+        uses: actions/cache@v4
+        with:
+          path: /var/cache/apt/archives
+          key: apt-${{ runner.arch }}-${{ hashFiles('.github/workflows/build.yml') }}
+          restore-keys: apt-${{ runner.arch }}-
+
       - name: Install dependencies
         run: |
-          sudo apt-get update
-          sudo apt-get install -y software-properties-common
-          sudo add-apt-repository -y ppa:ubuntu-support-team/meson
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             build-essential \
@@ -66,9 +70,6 @@ jobs:
             libxfixes-dev \
             libwayland-client0 \
             libwayland-dev
-          sudo apt-get clean autoclean --yes
-          sudo apt-get autoremove --yes
-          sudo rm -rf /var/cache/apt/archives* /var/lib/apt/lists/*
 
       - name: Build Debian package
         run: |

debian/rules

@@ -4,42 +4,40 @@
 export DH_VERBOSE = 1
 
 TARGETS = $(shell cat debian/targets | grep $(DEB_HOST_GNU_TYPE))
+NPROC := $(shell nproc)
 
 override_dh_clean:
 	dh_clean
 	rm -rf libmali-*/
 	rm -rf debian/libmali-*/
 
 override_dh_auto_configure:
-	for target in $(TARGETS); do \
-		export $$(scripts/parse_name.sh $$target); \
+	printf '%s\n' $(TARGETS) | xargs -P$(NPROC) -I{} sh -c '\
+		target="{}"; \
+		eval "$$(scripts/parse_name.sh $$target)"; \
 		dh_auto_configure --builddirectory=$$name -- \
 			-Darch=$${target%%-*} -Dgpu=$$gpu \
 			-Dversion=$$version -Dsubversion=$$subversion \
-			-Dplatform=$$platform -Dvendor-package=true -Dwrappers=enabled; \
-	done
+			-Dplatform=$$platform -Dvendor-package=true -Dwrappers=enabled'
 
 override_dh_auto_build:
 override_dh_auto_test:
 
 override_dh_auto_install:
-	for target in $(TARGETS); do \
-		export $$(scripts/parse_name.sh $$target); \
+	printf '%s\n' $(TARGETS) | xargs -P$(NPROC) -I{} sh -c '\
+		eval "$$(scripts/parse_name.sh {})"; \
 		dh_auto_install --builddirectory=$$name \
-			--destdir=debian/$$name; \
-	done
+			--destdir=debian/$$name'
 
 override_dh_makeshlibs:
-	for target in $(TARGETS); do \
-		export $$(scripts/parse_name.sh $$target); \
-		dh_makeshlibs -p$$name; \
-	done
+	printf '%s\n' $(TARGETS) | xargs -P$(NPROC) -I{} sh -c '\
+		eval "$$(scripts/parse_name.sh {})"; \
+		dh_makeshlibs -p$$name'
 
 override_dh_shlibdeps:
-	for target in $(TARGETS); do \
-		export $$(scripts/parse_name.sh $$target); \
-		dh_shlibdeps -p$$name -- -Sdebian/$$name; \
-	done
+	printf '%s\n' $(TARGETS) | xargs -P$(NPROC) -I{} sh -c '\
+		eval "$$(scripts/parse_name.sh {})"; \
+		dh_shlibdeps -p$$name -- -Sdebian/$$name'
 
 %:
 	dh $@ --buildsystem=meson