Allow psr/http-message 2

[derrabus]

No description provided.

[aimeos]

@Nyholm When will this PR merged an a new version tagged? At the moment, all composer installations break if psr/http-message:2.0 is required

[Nyholm]

Hey. Of course. Sorry for the delay

[mvorisek]

This has broken our stable releases wit PHP 7.4 as we require this package only:
https://github.com/atk4/ui/blob/5.0.0/composer.json#L56
and not "psr/http-message": "^1.0" explicitly.

Issue:

Fatal error: Declaration of class@anonymous::__toString() must be compatible
with Psr\Http\Message\StreamInterface::__toString(): string

I wonder if this is intended BC break and if this release should be untagged and released under v2.0.

[Nyholm]

Hey.

Thank you for the report. psr/http-message: 2 says it supports php 7.2.
Where is this anonymous class used? Is it your code or a library?

[mvorisek]

in our codebase - but it is BC break when "psr/http-message": "^1.0" is not required explicitly in user projects/libs

[Nyholm]

Yeah.
It seams like you have been using a dependency (psr/http-message), but not specified it in your composer.json. That is super easy to do, but it is dangerous because of situations like this.

I appreciate you reporting this and explaining how to fix it. That will probably help the next person in the same situation.