When I go to http://tools.wmflabs.org/xtools-dev/pages and do a search against almost any project except English Wikipedia, I get a client-side notice saying:
"es.wikipedia.org is not a valid project" or "plwiki is not a valid project", etc.
And then usually it reloads the page giving me a server error:
500: Internal Server Error An error has occurred within xTools. The server said: String could not be parsed as XML
So while the one bug for T163527 needed to be fixed, there was still more ways to improve getting project metadata within XTools. For that I've reworked a bunch of things, namely requiring a new parameter for the API path. This resolves our main issue, where before we were using addwiki's newFromPage to parse the HTML of a project page to get the API path. That to me is kind of crazy, and seems prone to error.
PR: https://github.com/x-tools/xtools-rebirth/pull/24
The other major change is we're getting most project metadata from the API via prop=siteinfo, as opposed to the wiki table in the meta database, which only gives us a handful of metadata. With prop=siteinfo we also have valuable things like the wiki path (/wiki/Article, may differ for 3rd party wikis), and the timezone, which we currently assume to be UTC. More PRs will follow to fix those issues and make XTools more 3rd-party-friendly, this PR is just about making the data accessible.