libostree-dev binary package in Ubuntu Focal amd64

 libostree is a library for managing bootable, immutable, versioned
 filesystem trees. It is like git in that it checksums individual files
 and has a content-addressed object store; unlike git, it "checks out"
 the files using hardlinks into an immutable directory tree. This
 can be used to provide atomic upgrades with rollback, history and
 parallel-installation, particularly useful on "fixed purpose" systems
 such as embedded devices. It is also used by the Flatpak application
 runtime system.
 .
 This package contains development headers and the pkg-config file for
 libostree.

Source package