Rerouted (regenerated, verified). Same repository and tag, but GitHub now builds the zip with different bytes, so it no longer matches the SHA-1 package.elm-lang.org recorded. The Lamdera package server serves a copy recovered from https://github.com/jxxcarlson/elm-l0-parser.
What we checked: Tag 1.2.2 is still on github.com/jxxcarlson/elm-l0-parser; its commit 6073124b189c is from 2021-12-10 00:52 UTC, before the version was published (2021-12-10 00:53 UTC); elm.json is byte-identical to package.elm-lang.org's; the exposed modules match docs.json; the zip's SHA-1 is not the published one (GitHub's zip no longer comes out byte for byte the same), so the contents were checked instead.
The Lamdera compiler uses this copy and prints a one-line notice saying so. elm itself fails to download this version.
Details · package.elm-lang.org's zip: https://github.com/jxxcarlson/elm-l0-parser/zipball/1.2.2/
Types of blocks.