How to alter languageswitcher to display as select element I am trying to get to grips with D8, and want to be able to use the language module's language switcher block. I am trying to alter the output to get it to display as a select element rather than a list.I tried creating block--languageswitcher.html.twig but couldn't see how to alter the list.

Looking into the module, I can see a function language_element_info_alter but cannot see how to use this to render a different output.

Do I need to use a block_alter or theme hook? In the LanguageBlock.php, the build() function returns an array with a #theme parameter set to links__language_block. Would this be what I need?
Yes, you could override the links__language_block template (links--language-block.html.twig) and print out a select there by hand. You would also need JS to make selecting something the same as clicking a link as an option element alone won't be able to trigger like a form.