# Buggy code
def git_object_by_path(self, path):
    import git

    path = os.path.relpath(os.path.realpath(path), self.git.working_dir)
    assert path.split(os.sep, 1)[0] != ".."

    self._try_fetch_from_remote()

    try:
        tree = self.git.tree(self.rev)
    except git.exc.BadName as exc:
        raise DvcException(
            "revision '{}' not found in git '{}'".format(
                self.rev, os.path.relpath(self.git.working_dir)
            ),
            cause=exc,
        )

    if not path or path == ".":
        return tree
    for i in path.split(os.sep):
        if not self._is_tree_and_contains(tree, i):
            # there is no tree for specified path
            return None
        tree = tree[i]
    return tree


# Traceback (ValueError)
ERROR: failed to pull data from the cloud - path is on mount 'F:', start on mount 'C:'
Traceback (most recent call last):
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\command\data_sync.py", line 46, in
do_run recursive=self.args.recursive,
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\repo\pull.py", line 24, in pull
recursive=recursive,
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\repo\fetch.py", line 27, in fetch
used, jobs, remote=remote, show_checksums=show_checksums
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\data_cloud.py", line 144, in pull
show_checksums=show_checksums,
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\remote\local\__init__.py", line 493, in pull
download=True,
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\remote\local\__init__.py", line 459, in _process
download=download,
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\remote\local\__init__.py", line 358, in status
local_exists = self.cache_exists(md5s)
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\remote\local\__init__.py", line 232, in cache_exists
return list(filter(lambda md5: not self.changed_cache_file(md5), md5s))
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\remote\local\__init__.py", line 232, in <lambda>
return list(filter(lambda md5: not self.changed_cache_file(md5), md5s))
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\remote\base.py", line 518, in changed_cache_file
actual = self.get_checksum(cache_info)
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\remote\base.py", line 275, in get_checksum
checksum = self.get_file_checksum(path_info)
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\remote\local\__init__.py", line 208, in get_file_checksum
return file_md5(path_info.path)[0]
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\site-packages\dvc\utils\__init__.py", line 48, in file_md5                      logger.info(msg.format(os.path.relpath(fname)))
File "c:\users\srg\appdata\local\continuum\anaconda3\envs\tf-keras\lib\ntpath.py", line 584, in relpath
path_drive, start_drive))                                                                                                                        ValueError: path is on mount 'F:', start on mount 'C:'

# Fixed code
def git_object_by_path(self, path):
    import git

    path = relpath(os.path.realpath(path), self.git.working_dir)
    assert path.split(os.sep, 1)[0] != ".."

    self._try_fetch_from_remote()

    try:
        tree = self.git.tree(self.rev)
    except git.exc.BadName as exc:
        raise DvcException(
            "revision '{}' not found in git '{}'".format(
                self.rev, os.path.relpath(self.git.working_dir)
            ),
            cause=exc,
        )

    if not path or path == ".":
        return tree
    for i in path.split(os.sep):
        if not self._is_tree_and_contains(tree, i):
            # there is no tree for specified path
            return None
        tree = tree[i]
    return tree