I put my home directory under version control. If I now start git-gui from my Gnome panel I can only work on this repository. The dialog that lets me browse for or enter a repository location or pick one that I used before is no longer there.
I could not find an according commandline or .gitconfig switch.
How can I force git-gui to display the dialog?
Create a file with the following contents and mark it executable:
#!/bin/sh
cd /
git gui
Save that file somewhere in your PATH (e.g. /usr/bin/my-git-gui). Then change your gnome-panel launcher to point to that file instead of git gui.
(git gui issues the prompt you want only if the working directory is not in a git repo. gnome-panel launchers set the working directory to ~, which in your case is a git repo; the script above is just a wrapper that sets the working directory to something that's hopefully not a git repo.)