@bdimcheff, thanks for your PR! By analyzing the history of the files in this pull request, we identified @taku0, @garbas and @abbradar to be potential reviewers.

hmmm i guess a file got moved in master since I branched off from unstable, one sec

ok I need to wait for the hydra to catch up because I don't want to recompile gcc and everything, but I'll keep an eye out when most of the upstream binaries are compiled

It's not good I didn't catch this (we have some sort of nondeterminism, maybe I have desktop schemas installed to environment by something -- I'll investigate later). Can you show the error visible when Firefox crashes? Also, what desktop environment do you use?

GLib-GIO-ERROR **: Settings schema 'org.gnome.system.proxy' is not installed and I'm running i3 from lightdm. It does look like (in nixpkgs) gnome/kde/xfce login sets all sorts of variables that seem like they may cause the nondeterminism.

I just tried nix-shell -p firefox --run "firefox" --pure which actually didn't crash when I tried to print, but it was missing all sorts of icons and stuff:

(firefox:1265): Gtk-WARNING **: Could not find the icon 'folder'. The 'hicolor' theme
was not found either, perhaps you need to install it.
You can get a copy from:
        http://icon-theme.freedesktop.org/releases

(firefox:1265): Gtk-WARNING **: Error loading theme icon 'folder' for stock: Icon 'folder' not present in theme Adwaita

(firefox:1265): Gtk-WARNING **: Error loading theme icon 'dialog-warning' for stock: Icon 'dialog-warning' not present in theme Adwaita

(firefox:1265): Gtk-WARNING **: Error loading theme icon 'dialog-question' for stock: Icon 'dialog-question' not present in theme Adwaita

I wonder if firefox is detecting some gnome3 stuff and so it's trying to use gnome3 everything, but with --pure there's not enough for it to even try?

Anyhow, my guess is if everything works with --pure it should work generally, no? If that's the goal I can play around with it a bit and see if I can get it working.

fwiw chrome[ium] still crashes for me on the native print dialog without the wrapper. I haven't tried --pure yet.

Unsetting XDG_DATA_DIRS should be enough to test this, I think. Some DEs put lots of stuff on that path.

It's really strange that wrapGapps didn't prevent #25505 on master; I'm sorry to have meddled with this at the layer of the wrapper – I didn't notice these are attempted on the unwrapped firefox already.

@vcunat yeah I actually don't know if my change is necessary on master because I was building off of the most recent nixpkgs unstable that passed in hydra, since I didn't want to rebuild everything locally. We can definitely hold off on this PR until your changes are live and I can test it in various ways.

Is this still a problem? nix-shell -p firefox-bin --pure --run 'firefox' (also for firefox) works for me with a recent master.

This also works for me (just printed this page)

yeah this works for me too... for some reason under kde i still get a crash, but with --pure I don't, but that might just be my fault somehow.