Automated reviews and snapcraft < 2.38

[jdstrand]

@jdstrand

Now that new versions of snapcraft are widely available (ie, 2.40 is in the snap’s stable channel and -updates for all Ubuntu releases (which LP and build.snapcraft.io pulls in automatically)), as of yesterday (2018/04/12) the review tools in the store now require the snap is created with -no-fragments (which snapcraft does as of 2.38).

The resquash test is essentially: checksum the original snap, unsquash the original snap, mksquash the unsquashed files with expected options, checksum the resquashed snap and compare it to the original. When we turned the resquashfs tests to enforce last month, most snaps (by far) passed the resquash test but we discovered a few scenarios where app snaps failed review:

1. Publishers using snapcraft < 2.38. To remedy, publishers should either: a. upgrade to snapcraft >= 2.38 (recommended) b. build the snap how you normally would, then run:

   $ unsquashfs /path/to/snap
   $ mksquashfs ./squashfs-root ./path/to/new/snap -noappend -comp xz -all-root -no-xattrs -no-fragments
   (then upload the resulting snap)
   

2. Publishers using electron-builder <20.14.7. To remedy, publishers should either: a. use lastest stable electron-builder (recommended) b. build the snap how you normally would, then run:

   $ unsquashfs /path/to/snap
   $ snapcraft pack ./squashfs-root
   (then upload the resulting snap)
   

   c. adjust package.json to use (latest stable will do this for you):

   {
     "devDependencies": {
       ...
       "electron-builder": "^20.9.2",
       ...
     },
     "build": {
       ...
       "linux": {
         ...
         "target": [
           ...
           "snap"
         ],
         ...
       },
       "snap": {
         ...
         "useTemplateApp": false
       },
       ...
     },
     ...
   }
       
   

In all of the above cases we’re simply ensuring that the snap that is published to the store is squashed with the expected options.