bwrap: Can't find source path
After the GNOME 3.34 update I'm having trouble compiling and running an application from GNOME Builder; it complains that
bwrap: Can't find source path /run/user/1000/doc/by-app/<app-id>: No such file or directory and then exits.
The issue was fixed by starting xdg-document-portal with
systemctl start --user xdg-document-portal, as that node was
inactive (dead). @borschty on #gimpnet#gnome:irc.gnome.org suggested that gnome-builder might be assuming that the path exists before the documents portal has been started, I have no flatpak packages so xdg-document-portal doesn't autostart.