We use a different .git Sub-Folder inner the Workspace for Git Repository.

Workspace Folder:
E:\SCM/WKS/safir_WAS/Template-Basis-20151013

Git Folder:
E:\SCM/WKS/safir_WAS/Template-Basis-20151013/GIT

The Build failed with:

17.07.2017 10:41:47 [WARNINGS] Parsing warnings in console log with parser Java Compiler (javac)
17.07.2017 10:41:47 <Git Blamer> Using GitBlamer to create author and commit information for all warnings.
17.07.2017 10:41:47 <Git Blamer> Getting blame results for all files in E:\SCM/WKS/safir_WAS/Template-Basis-20151013.
17.07.2017 10:41:47  > git.exe rev-parse "0f01e15e5cce133c426e9f9a2603b2b2c2adedb0^{commit}" # timeout=10
17.07.2017 10:41:47 ERROR: Build step failed with exception
17.07.2017 10:41:47 hudson.plugins.git.GitException: Command "git.exe rev-parse "0f01e15e5cce133c426e9f9a2603b2b2c2adedb0^{commit}"" returned status code 128:
17.07.2017 10:41:47 stdout:
17.07.2017 10:41:47 stderr: fatal: Not a git repository (or any of the parent directories): .git