Currently you always need to specify a git reponame (like migration.git) and a workspacename for the rtc workspace (Migration_Workspace).
To improve usabilty, have a default value for these two.
The question should be "Do you want to recreate the workspace (name)? [Y/n]"
Default is Yes. N will reuse the workspace
With following commands workspaces can be listed:
lscm list workspaces -n "NAME" -r "URL"