lungo self update replaces the command with the latest release of its channel. It installs a
release only when the release manifest’s signature chains to the keys built into the lungo
you run, the archive has the size and SHA-256 digest the manifest lists, and the command in it
reports the version it was published as; anything else is the new error LNG0112, and the
installed command is left as it is.
A lungo installed by Homebrew, apt or dnf, or built by cargo install, is not replaced by
lungo self update: it says what updates it (LNG0111). The packages mark the command they
install with a file named installed-by beside it.