Cannot modify files installed by `snap`

Snap partitions use SquashFS, which is basically a compressed, read-only disk image format that is usually used to create live CDs/DVDs. SquashFS was simply not designed to be read-write. To edit the contents, even something as simple as changing file permissions, cannot be done through a simple remount.

Your options are:

• Rebuild the SquashFS file system. The following resources should be helpful:

  • Modifying a squashfs
  • How to modify squashfs image

• Use OverlayFS to save changes separately.

If you would like to become a Snap developer, you might like to start with this tutorial to create your first snap.