I too am interested in how to properly setup the QT plugin path. The electrum package just crashes unless QT_PLUGIN_* is set appropriately. The expressions should be harmonized, I think or even unified if possible.

@ttuegel do you have insights on correct usage of QT_PLUGIN_* variables?

do you have insights on correct usage of QT_PLUGIN_* variables?

They should not be set. They will be set correctly when installed on NixOS or with nix-env. (This means, unfortunately, that Qt applications do not work with nix-build or nix-shell.) If set at build-time, the application tends to integrate poorly with non-KDE and non-NixOS systems.

Hrm, then I'll leave the original electrum as it is, though it is kind of poor ux to crash out-of-the-box if running directly from nixpkgs. Then again, it's simple enough to fix if you know how to ... @ttuegel I'm still a little unclear why it is that there were no problems of this kind with qt4? Simply a change in architecture between qt4 and 5?

Thanks, that is good to know! I've force pushed a version without the QT_QPA_PLATFORM_PLUGIN_PATH variable. I verified that it does indeed run OK if I install the package to my profile.

I'm still a little unclear why it is that there were no problems of this kind with qt4? Simply a change in architecture between qt4 and 5?

Qt 4 didn't use plugins this way while Qt 5 makes extensive use of plugins. We also only ever shipped one version of Qt 4 at a time, but we ship multiple Qt 5 versions; we must be very careful about plugin compatibility. We could (and once did) use wrappers to take care of this; then programs work the way developers expect, but not the way that users expect. So this was my compromise between developer and user experience. I don't like it, but I don't know how to do better right now. ☹️