`proc-macro-error` (dependency of `i18n-embed-fl`) is unmaintained

[str4d]

The last release of proc-macro-error was 3.5 years ago. It appears that the author of proc-macro-error has been AFK from their GitLab for around 2.5 years, which in particular means that proc-macro-error is not being updated to use syn 2 (see e.g. https://gitlab.com/CreepySkeleton/proc-macro-error/-/merge_requests/35).

From the discussions around proc-macro-error there appear to be two maintained alternatives:

• proc-macro2-diagnostics
• manyhow

[kellpossible]

@str4d thanks for the heads up!