The reason for the described behaviour is that snap applications are installed by default with confined permissions. This is a deliberate choice and you can read more on the subject here:
https://tutorials.ubuntu.com/tutorial/advanced-snap-usage#3
4. Handling interfaces and permissions in your snaps
The plugin removable-media seems to be declared in:
https://github.com/mmtrt/gitkraken/blob/master/snap/snapcraft.yaml
The snap connect for this plugin did not work for me either. (I am unsure the above was the correct git repository for this snap, as the author mentions not maintaining it any longer as it now released by Axosoft.)
Thus leaves you with few options:
(1) actively do something to make it work by contributing to the code (if possible)
(2) trust the application and install it with "devmode" permissions
(3) wait utill snap connect gitkraken:removable-media
starts working
In case you wish to proceed with option (2) and install the application with devmode permissions (you should know that you grant access to the app to anything your user would have access to):
sudo snap remove gitkraken
sudo snap install --devmode gitkraken
to verify if the installation happened as intended you can check for "devmode" by running the command "snap list" (see how this are supposed to have changed, you may have more snaps listed here, I have included only the one you should check)
snap list
Name Version Rev Tracking Publisher Notes
gitkraken 4.1.1 134 stable gitkraken✓ -
targeted outcome
Name Version Rev Tracking Publisher Notes
gitkraken 4.1.1 134 stable gitkraken✓ devmode
Cheers,
Happy Coding!
snap list
to the question. – N0rbert Jul 31 '18 at 19:58