ostree - stage files from an OSTree repository

Usage:

# Specify the ostree source kind
kind: ostree

# Optionally specify a relative staging directory
# directory: path/to/stage

# Specify the repository url, using an alias defined
# in your project configuration is recommended.
url: upstream:runtime

# Optionally specify a symbolic tracking branch or tag, this
# will be used to update the 'ref' when refreshing the pipeline.
track: runtime/x86_64/stable

# Specify the commit checksum, this must be specified in order
# to checkout sources and build, but can be automatically
# updated if the 'track' attribute was specified.
ref: d63cbb6fdc0bbdadc4a1b92284826a6d63a7ebcd

# For signed ostree repositories, specify a local project relative
# path to the public verifying GPG key for this remote.
gpg-key: keys/runtime.gpg