Not sure what's happening here, but it doesn't look right.
Composer installs started failing today saying that an existing commit doesn't exist.
We have had this package installed for years:
https://packagist.org/packages/jublonet/codebird-php
I see that the page seems to list active data for the project, but it links to this repo, which is empty but for a single file:
https://github.com/jublonet/codebird-php
If you look a the user who committed the file there, they've made several other commits on other repos of the same or similar file.