dvc: use realpath-ed paths consistently

Fixes #2127

dvc/repo/init.py

@@ -59,7 +59,7 @@ def init(root_dir=os.curdir, no_scm=False, force=False):
     Raises:
         KeyError: Raises an exception.
     """
-    root_dir = os.path.abspath(root_dir)
+    root_dir = os.path.realpath(root_dir)
     dvc_dir = os.path.join(root_dir, Repo.DVC_DIR)
     scm = SCM(root_dir)
     if isinstance(scm, NoSCM) and not no_scm:

dvc/scm/git/__init__.py

@@ -42,10 +42,10 @@ class Git(Base):
         from git.exc import InvalidGitRepositoryError
 
         try:
-            self.git = git.Repo(root_dir)
+            self.git = git.Repo(self.root_dir)
         except InvalidGitRepositoryError:
             msg = "{} is not a git repository"
-            raise SCMError(msg.format(root_dir))
+            raise SCMError(msg.format(self.root_dir))
 
         # NOTE: fixing LD_LIBRARY_PATH for binary built by PyInstaller.
         # http://pyinstaller.readthedocs.io/en/stable/runtime-information.html