IMO that's expected. What you see here is the template name. To which path that is resolved depends on which template files actually do exist in your application. Maybe we could add another column including the filename relative to the project directory though.

That's because @FOSUser/layout.html.twig is not a path at all. When you override a template, you don't change the template name. You change the source file being used for this name. The template being rendered is still called @FOSUser/layout.html.twig (and this is the reason why FOSUserBundle is able to use your overriding template without having to be told about its existence: it does not have a different name)

Thanks for your answer.
Maybe we can implement a visual effect (to define) to indicate that the template is overriden?

it's difficult to really see which templates are rendered

The list is clear, these are all "Rendered templates"

Is there any issue here ?

I'd say no :) Basically why do you want to know it's a vendor or app template upfront? It's being rendered either way...

Not that im against a little hint though, in terms of exposing as much as possible :)

I think the point about the template name not being a path but only a logical name is quite clear by now.

But I also see, that the there is a very valid use case here. If I am debugging an issue with wrong rendering, I want to see at a glance which actual template file was rendered and not just the logical name. Because when searching for a bug, the logical name doesn't help too much.

Maybe we can implement a visual effect (to define) to indicate that the template is overriden?

that would require extra work, because it would force to look for all potential location for this template name (to see whether there are multiple existing files) instead of just reading the info from the template object.
Thus, that's not even something the Twig loader allows doing (as its job is to find the source to use, not all other potential sources to ignore).

Perhaps showing the relative path could help a bit to quickly understand which file was rendered:

Or to be more compact as actual. We can check if the path begins by 'vendor/'. And if not then we can show a little button or message
@apfelbox yes. I was debugging too and that was the origin of my question.

I like the proposal by @yceruto, agree a filepath reference is more recognizable then its logical name. Currently you have to hover each link for that.

I don't see any real reason to treat vendor/ templates any different then non-vendor templates, e.g. visually. That's not really relevant IMHO.

I would just take the proposal by @yceruto as is. 👌

We could also add a new option to the debug:twig command to look for template paths:

$ bin/console debug:twig --find=@FOSUser/layout.html.twig
templates/bundles/FOSUserBundle/layout.html.twig (default)
vendor/friendsofsymfony/user-bundle/Resources/views/layout.html.twig

We would see all the possible templates that match the given name and the search could be easier.

Proposal #27978 to improve the Twig panel is ready ;)

and see #27981 for a debug command ;)