This dependency was introduced by f5f258a by rvogel.

And the failing tests were caused by bug 76584.

Thank you, @hashar. I tried to output some diagnostic information, which contained binary data, for a test that had succeeded on my development server but failed when run on MediaWiki gerrit. I sanitised the output, and this issue disappeared, although the test still fails.

In T315589#8167782, @Yaron_Koren wrote:

Basically, I think this can be done by adding three new parameters to the #get_*_data functions: "display template", "additional values" and "display format". This would then allow us to get rid of the #external_value and all the "...external_table" parser functions.

Resolved, in reasonable limits.

Upgrade again. Remove the quotes from data, order by and group by.

1. Upgrade again.
2. Make sure that $egExternalData['myDatabase']['type'] = 'postgres'.
3. Remove all quotes from {{#get_db_data:}}.

Resolved by expanding {{{…}}} in the optional second parametre before expanding templates and parser functions.

You can upgrade and test.

In T315402#8162281, @Yaron_Koren wrote:

What would be the benefit of this?

Bracket notation should be used in this case, e.g., $['@a'].

This extension used to define a specific tag for only a short time. That tag, whatever it was called, has been removed. Now, any tag which may be defined by this extension comes from the tag emulation mode.

If Composer for this extension is sorted out, perhaps something can be done about T259743, so that manual composer require mongodb/mongodb is no longer necessary to access MongoDB.

External Data is not published at Packagist anyway.

In T302049#7720871, @Reedy wrote:

What version of MobileFrontend are you using?

I thought I was using REL1_35. Deleted the extension folder and cloned it again; the error disappeared. It seems I had messed it up with the IDE.