Source repository is not detected

[MarcelWaldvogel]

This is essentially a duplicate (or re-occurence/regression/…) of #2425, just with different repositories.

Problem description

Several of the repositories I have been working on have not had their source listed or had stopped their source being listed even though neither the repository nor the metadata had changed. I wasted a lot of time (and some useless releases) under the impression that it was my problem. Thanks to #2121 I learned that libraries.io only considers some very specific project_urls keys to be repository links, unlike PyPI, which puts GitLab and GitHub icons next to the links depending on the value of the URL. Now the former GitLab and GitHub keys have been renamed to Source or Source Code; several of them have the link in their url field, sometimes as well.

Still, they do not show up as having source code available, and therefore also no READMEs etc. One of them, git-timestamp, even stopped having the source listed, despite no change to the url (and continued absence of project_urls) fields.

Other projects affected by the same issue and valid url or project_url['Source']fields are: deltat and autoblockchainify. fake-super had a url pointing to a repository until recently, but it was never picked up.

Possible solution

It seems that a large fraction of my repositories need a resync (as in #2425). Probably there are many other packages out there which might suffer from the same problem.

Documenting repository selection

The repository URL selection is: Take the first of project_url['Source'] and project_url['Source Code'], and then check whether it is a GitHub, GitLab or BitBucket URL. If it is not, try again with the first of url or project_url['Homepage'].

(The goal of the longish description is that it might help others having the same problem.)