release.scmVersion always return "abc" when using with GitHub

[xmlking]

release.scmVersion is always returning abc while using with GitHub.
expected git's commit# as release.scmVersion value.
The documentation also not clear how release command automatically guess the next available version number in case using with github.

[ari]

The code to have the plugin grab the current tag (if any) has not yet been written. But there is no code to guess the next release number, since that isn't part of the workflow I use this plugin for.