We plan to make SimplePie’s HTTP fetcher component replaceable with implementations of the PSR-18 contract. In order to do so, we would need to add a dependency on psr/http-client Composer library.

Now while is it possible to avoid mandatory dependency on the library, it would mean duplicating the interfaces and adding extra code for bridging that we would have to maintain, complicating the codebase forever until next BC break window.

@Art4 pointed out that @Simounet’s LeedRSS and @ophian’s styx still use the bundle so I want to ask if removal of the bundle would be problematic for you.

Alternately, we could stuff the interfaces into the bundle, wrapping them in if (!class_exists('...')) blocks but that could hide dependency version mismatches if app pulls a newer version of the interface.