Latest updates break sites on PHP 7.4

Provided an MR to fix this, please review.

It does. See [£3400004]. This is why it was changed.

What version of Drupal are you using?

This is happening on one of the last 9.5.11 Drupal sites that the customer has not approved the budget for the update yet.

Drupal 9 minimum php requirements → are php 8. In your case, I would use the patch, but maintainers try to stick with the Drupal requirements.

@shelane while I see and accept your point about Drupal 9, the declaration of the function's return type is still incorrect. It always returns MarkupInterface and never a string. I think this should still be fixed, even if it's for a different reason.

Except that it does. I had it as MarkupInterface and then an error was reported in the issue I linked in #4. For php 8, we can accept either.

That's interesting, because the declaration of \Drupal\Core\Render\RendererInterface::render says, that it certainly only returns MarkupInterface.

I've checked for implementations of that method, and that's just one: \Drupal\Core\Render\Renderer::render. That one returns the result from \Drupal\Core\Render\Renderer::doRender and that in fact returns empty strings under some circumstances.

This looks like a core bug in my view.

I have updated the MR such that it does not declare the return type any longer. That's the only way to keep it working on PHP 7.4 and also make sure that the string return type doesn't cause issue on PHP 8.1 - not sure how we get core to fix the issue at the source, so that all the declarations should be reliable.

I think a notice should be put on the module page to warn users that this module is not compatible with php 7.4.
This would help avoid problems on sites that cannot yet upgrade to php 8.x / Durpal 10

The patch solves the problem in my case.

Cheers!