Installing ddd in Silverblue toolbox container fails: xdg-utils conflicts with flatpak-xdg-utils

$ sudo dnf install vim less gcc make ddd gdb g++
The downloaded packages were saved in cache until the next successful transaction.
You can remove cached packages by executing 'dnf clean packages'.
Error: Transaction check error:
  file /usr/bin/xdg-email from install of xdg-utils-1.1.3-4.fc30.noarch conflicts with file from package flatpak-xdg-utils-1.0.0-2.fc30.x86_64
  file /usr/bin/xdg-open from install of xdg-utils-1.1.3-4.fc30.noarch conflicts with file from package flatpak-xdg-utils-1.0.0-2.fc30.x86_64

How can I fix this? I don’t really need xdg-utils, I just want to install some things for C/C++ programming…


Edit: As it seems, only ddd is pushing this dependency in.