Unfortunately rally-app-builder clone
functionality predates newer developments and the availability of source code of catalog apps from RallyApps/app-catalog, so it does not support drilling down those directories.
clone RallyApps StoryBoard
works because there is a StoryBoard app at that location. There is no ReleaseBurnup there. ReleaseBurnup code is not available.
Here are the steps to build an app from javascript source files from GitHub app-catalog repository
Prerequisites:
Get the source to a local directory (you may either fork the app-catalog repo, or download zip from the same location):
in terminal, cd to the directory of the app you want to work on, and call this command:
rally-app-builder build
.
As a result a deploy folder is created with App.html and App-uncompressed.html inside, and App-debug.html is created in the root folder of the app.
These steps make sense only if you intent to customize the catalog app and want to use the source as basis. If you want to use a catalog app as it was designed, install the app directly from the AppCatalog as described in this help document.