I can reproduce the issue locally and reverting Replace deprecated url functions in Skin class fixes it, so I guess the replacement functions work slightly differently.

@Nikki points out that the donate link is also affected (points to https://www.wikidata.org/wiki///donate.wikimedia.org/wiki/Special:FundraiserRedirector%3Futm_source%3Ddonate%26utm_medium%3Dsidebar%26utm_campaign%3DC13_wikidata.org%26uselang%3Den).

Change #1029264 had a related patch set uploaded (by Lucas Werkmeister; author: Lucas Werkmeister):

[mediawiki/core@master] Revert "Replace deprecated url functions in Skin class"

https://gerrit.wikimedia.org/r/1029264

Change #1029522 had a related patch set uploaded (by Lucas Werkmeister; author: Lucas Werkmeister):

[mediawiki/core@master] Skin: Fix UrlUtils calls

https://gerrit.wikimedia.org/r/1029522

I fixed the links locally until this is fixed. These edits should be undone once the underlying issue is fixed:

• https://www.wikidata.org/wiki/MediaWiki:Sitesupport-url
• https://www.wikidata.org/wiki/MediaWiki:Wikibase-queryservice-url

Change #1029264 abandoned by Lucas Werkmeister:

[mediawiki/core@master] Revert "Replace deprecated url functions in Skin class"

Reason:

superseded by I050ed65624

https://gerrit.wikimedia.org/r/1029264

Also broke the techblog link on mediawiki.org

Change #1029522 merged by jenkins-bot:

[mediawiki/core@master] Skin: Fix UrlUtils calls

https://gerrit.wikimedia.org/r/1029522

Change #1029552 had a related patch set uploaded (by Lucas Werkmeister; author: Lucas Werkmeister):

[mediawiki/core@wmf/1.43.0-wmf.4] Skin: Fix UrlUtils calls

https://gerrit.wikimedia.org/r/1029552

Change #1029552 merged by jenkins-bot:

[mediawiki/core@wmf/1.43.0-wmf.4] Skin: Fix UrlUtils calls

https://gerrit.wikimedia.org/r/1029552

Mentioned in SAL (#wikimedia-operations) [2024-05-09T20:47:22Z] <jhuneidi@deploy1002> Started scap: Backport for [[gerrit:1029552|Skin: Fix UrlUtils calls (T364539)]]

Mentioned in SAL (#wikimedia-operations) [2024-05-09T20:49:51Z] <jhuneidi@deploy1002> jhuneidi and lucaswerkmeister: Backport for [[gerrit:1029552|Skin: Fix UrlUtils calls (T364539)]] synced to the testservers (https://wikitech.wikimedia.org/wiki/Mwdebug)

Mentioned in SAL (#wikimedia-operations) [2024-05-09T21:11:04Z] <jhuneidi@deploy1002> Finished scap: Backport for [[gerrit:1029552|Skin: Fix UrlUtils calls (T364539)]] (duration: 23m 42s)

This should be fixed now, but the sidebar is cached for one day, so we should only delete the overrides tomorrow (or later). Let’s leave the task open until then, IMHO.

In T364539#9783142, @Lydia_Pintscher wrote:

I fixed the links locally until this is fixed. These edits should be undone once the underlying issue is fixed:

• https://www.wikidata.org/wiki/MediaWiki:Sitesupport-url
• https://www.wikidata.org/wiki/MediaWiki:Wikibase-queryservice-url

I think it would be okay to undo those edits now.

Done!