Hello technomad The reason is that google is already added to your search engines list you can check that by going to Menu - options - Search.

https://user-media-prod-cdn.itsre-sumo.mozilla.net/uploads/images/2019-09-07-00-29-34-9972fa.png

I removed all search engines except one and even if I hadn't I would expect Firefox still to show the add search engine option.

You could try the Google UK add-on: https://addons.mozilla.org/firefox/addon/googleuk/

I was hoping to find out why the documented method to add a search engine doesn't work.

technomad said

I was hoping to find out why the documented method to add a search engine doesn't work.

The article Add or remove a search engine in Firefox was recently updated and now includes the following note:

Note: If you removed one of the default search engines built into Firefox, such as Google, you can't visit the website to add it back. You'll have to restore the default search engines. See Remove search engines and Adding back a removed search engine, <snip>

The article doesn't cover the "edge" case of not being able to add a different version of a built-in Search engine, like GoogleUK, from the address bar.

My guess is that Firefox considers all versions of the Google search engine as built-in, so you can't use the address bar method to add GoogleUK (maybe that's a reason why the Google UK add-on was created).

The people who answer questions here are mostly volunteers (like me). You can provide feedback to Mozilla (go to the Firefox Help menu and select Submit Feedback... or use this link). You can also file a bug report at https://bugzilla.mozilla.org/.

Hi technomad, separate and apart from possible duplicate engine issues, the site needs to include an OpenSearch link tag in the page in order for Firefox to show the option on the Page Actions (•••) menu.

Taking YouTube as an example, and understanding that I'm based in the U.S., you'll find this tag in the page source:

<link rel="search" type="application/opensearchdescription+xml" href="https://www.youtube.com/opensearch?locale=en_US" title="YouTube">

The https://www.google.co.uk/ main page and results pages do not include an OpenSearch link tag pointing to an XML file with the official URLs, so the menu feature isn't shown.

You would need to use a different method to add the search engine, such as the Add-ons site or Mycroft, where people have figured out the URLs and built the OpenSearch XML file or an equivalent extension.

jscher2000 said

separate and apart from possible duplicate engine issues, the site needs to include an OpenSearch link tag in the page in order for Firefox to show the option on the Page Actions (•••) menu.

Thanks. I made some edits to the article.

I used to use mycroft but this time it returned strange results. I have started reading the OpenSearch documentation.

It all became more difficult when Google started ignoring the country of the domain when returning results. I live in multiple places and would like an simple way to choose which results I want to see without setting a preference.

technomad said

I live in multiple places and would like an simple way to choose which results I want to see without setting a preference.

That helps explain your username. But I digress.

If you can extract the command line parameter that the Search Tools add to the URL of the results page when it is set the way you want, you could set up a custom search engine plugin using this add-on (it uses a third party website to generate the XML file, so as with Mycroft, nothing too personal should be in the query):

https://addons.mozilla.org/firefox/addon/search-engines-helper/