How to pull,build partA and only then pull,build partB?

snapcraft
1

The Chromium-ffmpeg snap is a content snap that provides Ffmpeg codecs for browsers based in Chromium.

Several different versions of Ffmpeg need to be provided. The same number of Chromium tarballs need to be fetched and unpacked to build them, each of them is its own part.

Because all parts’ life-cycles are run at a time before going to the next lifecycle, all tarballs are fetched and unpacked at once. This exhausts the disk space of the builder.

This would be easily solvable if each part could be run up to build before proceeding to the pull of the next part, as then I could delete all the part’s source code when it was done building, releasing the most part of disk space the part was claiming.

How to solve this?

2

I’m setting with this hack:

Stuff everything in a single part (combining all the parts’ build-packages) and have its override-build manually fetch each tarball (wget/curl/you name it), extract it, manually build it and then remove the sources. As illustration, here is the full context diff.

diff --git a/snapcraft.yaml b/snapcraft.yaml
index a1eb3bc..2117679 100644
--- a/snapcraft.yaml
+++ b/snapcraft.yaml
@@ -1,315 +1,124 @@
 name: chromium-ffmpeg
 version: "116575-116569-115541-115016"
 summary: FFmpeg codecs (free and proprietary) for use by third-party browser snaps
 description: |
  This package provides a chromium-ffmpeg content interface that third-party
  browser snaps can connect to to get access to a host of proprietary codecs for
  web content that they might not be allowed to redistribute themselves.
 confinement: strict
 base: core22
 
 slots:
   chromium-ffmpeg-115016: # chromium 124.0.6367.118
     interface: content
     source:
       read:
         - $SNAP/chromium-ffmpeg-115016/chromium-ffmpeg
   chromium-ffmpeg-115541: # chromium 125.0.6420.0
     interface: content
     source:
       read:
         - $SNAP/chromium-ffmpeg-115541/chromium-ffmpeg
   chromium-ffmpeg-116569: # chromium 127.0.6533.4.tar.xz
     interface: content
     source:
       read:
         - $SNAP/chromium-ffmpeg-116569/chromium-ffmpeg
   chromium-ffmpeg-116575: # chromium 130.0.6683.2
     interface: content
     source:
       read:
         - $SNAP/chromium-ffmpeg-116569/chromium-ffmpeg
 
 parts:
   build:
     plugin: dump
     source: build
     organize:
       '*' : build/
     override-prime: ""
   chromium-ffmpeg-115016:
-    after: [build, chromium-ffmpeg-115541]
+    after: [build]
     plugin: nil
     source: https://commondatastorage.googleapis.com/chromium-browser-official/chromium-124.0.6367.118.tar.xz
     source-checksum: sha512/7615e301d02e2d06f64a75d601b64089c8f528ab546745a358fd521cb26d63b15dbc3f1faa4952d1d510bf0c2a132301023b8e179a21e26cf1c48a80e1650e3f
     build-snaps:
-      - llvm-chromium
-    build-packages:
-      - chrpath
-      - cmake
-      - elfutils
-      - gperf
-      - libatk1.0-dev
-      - libatk-bridge2.0-dev
-      - libcups2-dev
-      - libevdev-dev
-      - libgbm-dev
-      - libglib2.0-dev
-      - libgtk-3-dev
-      - libnss3-dev
-      - libpango1.0-dev
-      - mesa-common-dev
-      - ninja-build
-      - python3
-      - quilt
-      - rustc
-    build-environment:
-      - CC:  /snap/llvm-chromium/current/bin/clang
-      - CXX: /snap/llvm-chromium/current/bin/clang++
-      - AR:  /snap/llvm-chromium/current/bin/llvm-ar
-    override-pull: |
-      craftctl default
-      # Find the space offenders, builders are getting out of space.
-      # Top offenders so far and whether they are required (R) or can be
-      # deleted (D) for a successful build:
-      #   R 292M    llvm-build
-      #   R 316M    blink
-      #     367M    tflite
-      #     372M    catapult
-      #   R 442M    devtools-frontend
-      #   R 956M    dawn
-      #   D 1,2G    rust-toolchain
-      #   R 1,3G    swiftshader
-      #   R 1,7G    angle
-      #   D 1,9G    llvm
-      #   D 4,4G    rust-src
-      du -sh third_party/*|sort -h
-      rm -rf third_party/{rust-src,llvm,rust-toolchain}
-    override-build: |
-      set -eux
-      rm -rf $SNAPCRAFT_PART_SRC/*
-      VERSION=115016
-      QUILT_PATCHES=$SNAPCRAFT_STAGE/build/$VERSION quilt push -a
-      python3 tools/gn/bootstrap/bootstrap.py --skip-generate-buildfiles
-      OUT=out/ffmpeg
-      mkdir -p $OUT
-      cp $SNAPCRAFT_STAGE/build/$VERSION/args.gn $OUT/
-      if [ $CRAFT_TARGET_ARCH = "armhf" ]; then
-        # Do not build with ThinLTO either, because it requires lld
-        echo "use_thin_lto = false" >> $OUT/args.gn
-        # Do not build with NEON on armhf (https://launchpad.net/bugs/1884856)
-        echo "arm_use_neon = false" >> $OUT/args.gn
-      fi
-      out/Release/gn gen $OUT
-      ninja -C $OUT libffmpeg.so
-      DEST=$SNAPCRAFT_PART_INSTALL/chromium-ffmpeg-$VERSION/chromium-ffmpeg
-      mkdir -p $DEST
-      cp $OUT/libffmpeg.so $DEST/
-      rm -rf *
-  chromium-ffmpeg-115541: # chromium 125
-    after: [build, chromium-ffmpeg-116569]
-    plugin: nil
-    source: https://commondatastorage.googleapis.com/chromium-browser-official/chromium-125.0.6420.0.tar.xz
-    source-checksum: sha512/32e351b4d8309d2db0e1859dc3e99e3a63c2689ed21da4cf686faf71c767994c04ea745a3e581e1944450414e1fa1f0b4278ac71ef77f4f02e56e6b68cf9ca00
-    build-snaps:
-      - llvm-chromium
-    build-packages:
-      - chrpath
-      - cmake
-      - elfutils
-      - gperf
-      - libatk1.0-dev
-      - libatk-bridge2.0-dev
-      - libcups2-dev
-      - libevdev-dev
-      - libgbm-dev
-      - libglib2.0-dev
-      - libgtk-3-dev
-      - libnss3-dev
-      - libpango1.0-dev
-      - mesa-common-dev
-      - ninja-build
-      - python3
-      - quilt
-      - rustc
-    build-environment:
-      - CC:  /snap/llvm-chromium/current/bin/clang
-      - CXX: /snap/llvm-chromium/current/bin/clang++
-      - AR:  /snap/llvm-chromium/current/bin/llvm-ar
-    override-pull: |
-      craftctl default
-      # Find the space offenders, builders are getting out of space.
-      # Top offenders so far and whether they are required (R) or can be
-      # deleted (D) for a successful build:
-      #   R 292M    llvm-build
-      #   R 316M    blink
-      #     367M    tflite
-      #     372M    catapult
-      #   R 442M    devtools-frontend
-      #   R 956M    dawn
-      #   D 1,2G    rust-toolchain
-      #   R 1,3G    swiftshader
-      #   R 1,7G    angle
-      #   D 1,9G    llvm
-      #   D 4,4G    rust-src
-      du -sh third_party/*|sort -h
-      rm -rf third_party/{rust-src,llvm,rust-toolchain}
-    override-build: |
-      set -eux
-      rm -rf $SNAPCRAFT_PART_SRC/*
-      VERSION=115541
-      QUILT_PATCHES=$SNAPCRAFT_STAGE/build/$VERSION quilt push -a
-      python3 tools/gn/bootstrap/bootstrap.py --skip-generate-buildfiles
-      OUT=out/ffmpeg
-      mkdir -p $OUT
-      cp $SNAPCRAFT_STAGE/build/$VERSION/args.gn $OUT/
-      if [ $CRAFT_TARGET_ARCH = "armhf" ]; then
-        # Do not build with ThinLTO either, because it requires lld
-        echo "use_thin_lto = false" >> $OUT/args.gn
-        # Do not build with NEON on armhf (https://launchpad.net/bugs/1884856)
-        echo "arm_use_neon = false" >> $OUT/args.gn
-      fi
-      out/Release/gn gen $OUT
-      ninja -C $OUT libffmpeg.so
-      DEST=$SNAPCRAFT_PART_INSTALL/chromium-ffmpeg-$VERSION/chromium-ffmpeg
-      mkdir -p $DEST
-      cp $OUT/libffmpeg.so $DEST/
-      rm -rf *
-  chromium-ffmpeg-116569: # chromium 127
-    after: [build]
-    plugin: nil
-    source: https://commondatastorage.googleapis.com/chromium-browser-official/chromium-127.0.6533.4.tar.xz
-    source-checksum: sha512/b203c016978683402ab08a171326bb1fd41921de4cad46945af5fefb0983ecc07b15a5f2911d0282caeb459a243b2adaa99809172c632109950ff24ffebf3fd9
-    build-snaps:
-      - llvm-chromium
+      - llvm-chromium/beta
     build-packages:
       - chrpath
       - cmake
       - elfutils
       - gperf
       - libatk1.0-dev
       - libatk-bridge2.0-dev
       - libcups2-dev
       - libevdev-dev
       - libgbm-dev
       - libglib2.0-dev
       - libgtk-3-dev
       - libnss3-dev
       - libpango1.0-dev
       - mesa-common-dev
       - ninja-build
       - python3
       - quilt
       - rustc
+      - wget
     build-environment:
       - CC:  /snap/llvm-chromium/current/bin/clang
       - CXX: /snap/llvm-chromium/current/bin/clang++
       - AR:  /snap/llvm-chromium/current/bin/llvm-ar
     override-pull: |
       craftctl default
       # Find the space offenders, builders are getting out of space.
       # Top offenders so far and whether they are required (R) or can be
       # deleted (D) for a successful build:
       #   R 292M    llvm-build
       #   R 316M    blink
       #     367M    tflite
       #     372M    catapult
       #   R 442M    devtools-frontend
       #   R 956M    dawn
       #   D 1,2G    rust-toolchain
       #   R 1,3G    swiftshader
       #   R 1,7G    angle
       #   D 1,9G    llvm
       #   D 4,4G    rust-src
       du -sh third_party/*|sort -h
       rm -rf third_party/{rust-src,llvm,rust-toolchain}
     override-build: |
       set -eux
       rm -rf $SNAPCRAFT_PART_SRC/*
-      VERSION=116569
-      QUILT_PATCHES=$SNAPCRAFT_STAGE/build/$VERSION quilt push -a
-      python3 tools/gn/bootstrap/bootstrap.py --skip-generate-buildfiles
-      OUT=out/ffmpeg
-      mkdir -p $OUT
-      cp $SNAPCRAFT_STAGE/build/$VERSION/args.gn $OUT/
-      if [ $CRAFT_TARGET_ARCH = "armhf" ]; then
-        # Do not build with ThinLTO either, because it requires lld
-        echo "use_thin_lto = false" >> $OUT/args.gn
-        # Do not build with NEON on armhf (https://launchpad.net/bugs/1884856)
-        echo "arm_use_neon = false" >> $OUT/args.gn
-      fi
-      out/Release/gn gen $OUT
-      ninja -C $OUT libffmpeg.so
-      DEST=$SNAPCRAFT_PART_INSTALL/chromium-ffmpeg-$VERSION/chromium-ffmpeg
-      mkdir -p $DEST
-      cp $OUT/libffmpeg.so $DEST/
-      rm -rf *
-  chromium-ffmpeg-116575: # chromium 130
-    after: [build]
-    plugin: nil
-    source: https://commondatastorage.googleapis.com/chromium-browser-official/chromium-130.0.6683.2.tar.xz
-    source-checksum: sha512/5406523316ab1f378660fdcfbfd4ba0a372e2b56dbb8f04f9906b822cb3778d90fad5fa1df7dc183ce288e2a4cb06880c6a473c792c22a9642d15f6aafcff5c6
-    build-snaps:
-      - llvm-chromium
-    build-packages:
-      - chrpath
-      - cmake
-      - elfutils
-      - gperf
-      - libatk1.0-dev
-      - libatk-bridge2.0-dev
-      - libcups2-dev
-      - libevdev-dev
-      - libgbm-dev
-      - libglib2.0-dev
-      - libgtk-3-dev
-      - libnss3-dev
-      - libpango1.0-dev
-      - mesa-common-dev
-      - ninja-build
-      - python3
-      - quilt
-      - rustc
-    build-environment:
-      - CC:  /snap/llvm-chromium/current/bin/clang
-      - CXX: /snap/llvm-chromium/current/bin/clang++
-      - AR:  /snap/llvm-chromium/current/bin/llvm-ar
-    override-pull: |
-      craftctl default
-      # Find the space offenders, builders are getting out of space.
-      # Top offenders so far and whether they are required (R) or can be
-      # deleted (D) for a successful build:
-      #   R 292M    llvm-build
-      #   R 316M    blink
-      #     367M    tflite
-      #     372M    catapult
-      #   R 442M    devtools-frontend
-      #   R 956M    dawn
-      #   D 1,2G    rust-toolchain
-      #   R 1,3G    swiftshader
-      #   R 1,7G    angle
-      #   D 1,9G    llvm
-      #   D 4,4G    rust-src
-      du -sh third_party/*|sort -h
-      rm -rf third_party/{rust-src,llvm,rust-toolchain}
-    override-build: |
-      set -eux
-      rm -rf $SNAPCRAFT_PART_SRC/*
-      VERSION=116575
+
+      main(){
+      VERSION=$1
       QUILT_PATCHES=$SNAPCRAFT_STAGE/build/$VERSION quilt push -a
       python3 tools/gn/bootstrap/bootstrap.py --skip-generate-buildfiles
       OUT=out/ffmpeg
       mkdir -p $OUT
       cp $SNAPCRAFT_STAGE/build/$VERSION/args.gn $OUT/
       if [ $CRAFT_TARGET_ARCH = "armhf" ]; then
         # Do not build with ThinLTO either, because it requires lld
         echo "use_thin_lto = false" >> $OUT/args.gn
         # Do not build with NEON on armhf (https://launchpad.net/bugs/1884856)
         echo "arm_use_neon = false" >> $OUT/args.gn
       fi
       out/Release/gn gen $OUT
       ninja -C $OUT libffmpeg.so
       DEST=$SNAPCRAFT_PART_INSTALL/chromium-ffmpeg-$VERSION/chromium-ffmpeg
       mkdir -p $DEST
       cp $OUT/libffmpeg.so $DEST/
-      rm -rf *
+      rm -rf * .pc
+      }
+
+      main 115016
+
+      wget -q -O- https://commondatastorage.googleapis.com/chromium-browser-official/chromium-130.0.6683.2.tar.xz | tar xJ --strip-components=1
+      main 116575
+
+      wget -q -O- https://commondatastorage.googleapis.com/chromium-browser-official/chromium-125.0.6420.0.tar.xz | tar xJ --strip-components=1
+      ls . ..
+      main 115541
+
+      wget -q -O- https://commondatastorage.googleapis.com/chromium-browser-official/chromium-127.0.6533.4.tar.xz | tar xJ --strip-components=1
+      main 116569