No error message when PHP "intl" extension is not enabled

Hello.

I've spent a lot of my time searching for a "bug".

I am using Windows7 with XAMPP (so Apache 2.x) with PHP 7.4x.

I had a headache while searchig for a (not) bug.

It seems that I had INTL extension disabled in my PHP.
But there is no error/info message about this, nothing.
Access or Error log messages - clean.

It would be nice to have some info while I see "Whooops! .... snag.... try again later" on the screen.

I am using CI4 for the first time. I did not search for dependencies description, but I wanted to load it as fast as I can.
CI_ENVIRONMENT constant did not help (changing to "development").

There are a lot of extensions in PHP. How would I know which one to choose, to remove my problem ?

I wrote it here, just to make sure, that there is another way to find the error about missing loaded extension.
Is there a way ? (skipping testing one by one of course)