Thanks for the answer Gary.
The problem is that I don't have this rifle.conf.
$ ranger --copy-config=rifle.conf
Unknown config file `rifle.conf'
$ ranger --copy-config=rifle
Unknown config file `rifle'
'locate rifle', does not give anything. I precise that I installed ranger using the usual fedora repos.
In .config/ranger I have :
apps.py apps.pyo bookmarks commands.py commands.pyo history keys.py keys.pyo options.py options.pyo scope.sh tagged
I tried to edit apps.py. I have this section where I just changer vim into gvim -v, but it didn't work :
# Often a programs invocation is trivial. For example:
# vim test.py readme.txt [...]
# This could be implemented like:
# @depends_on("vim")
# def app_vim(self, c):
# return tup("vim", *c.files)
# Instead of creating such a generic function for each program, just add
# its name here and it will be automatically done for you.
CustomApplications.generic('gvim -v', 'fceux', 'elinks', 'wine', 'zsnes', 'javac')