Is it possible to use as optional dependency a GPL dependency in a commercial product?
My idea is to ask the user when installing my product if he wants to install a GPL dependency. Is it possible to do that?
Closest example I have seen is with installing Audacity. Though Audacity is also open source the mp3 encoder used by it (lame) is of a non compatible license and requests user to manually install and provide path to it. As mentioned in the comments as long as it is not linked you should be fine to request the user to install any library. I feel the exception might be in the case of AGPL license. I am not sure about that. But that will really impact if it is a online application.