compare all built Fuchsia packages with a prior package snapshot
usage: fx delta [[--name|-n NAME] | [--source|-s PATH]] [--build] [--help-delta] [DELTA_ARGS...]
Compare metadata of all Fuchsia packages with a prior package snapshot.
--name|-n NAME Set the NAME of the source package snapshot (Default: "system")
--source|-s PATH Read the source snapshot from the specified PATH (Default: $FUCHSIA_BUILD_DIR/snapshots/$NAME.snapshot)
--help-delta Show command line help for "pm delta"
--build Build the current package snapshot before comparing it to the previously saved snapshot
DELTA_ARGS Unknown arguments are passed through to "pm delta"