Command running: ['update'], cwd: /home/gulnara/Documents/tpcc/tpcc-course-2020
Platform: Linux-4.15.0-88-generic-x86_64-with-Ubuntu-18.04-bionic
C++ compiler: /usr/bin/clang++-8 (clang version 8.0.0-3~ubuntu18.04.2 (tags/RELEASE_800/final))
Python: 3.6.9, CPython, /home/gulnara/Documents/tpcc/tpcc-course-2020/client/venv/bin/python
Repository root directory: /home/gulnara/Documents/tpcc/tpcc-course-2020
Git current commit: 8ffb8f60c7a50f1660de4566159552c1d1358cb7

Updating tasks repository

From https://gitlab.com/Lipovsky/tpcc-course-2020
 * branch            master     -> FETCH_HEAD
fatal: Unable to create '/home/gulnara/Documents/tpcc/tpcc-course-2020/.git/index.lock': File exists.

Another git process seems to be running in this repository, e.g.
an editor opened by 'git commit'. Please make sure all processes
are terminated then try again. If it still fails, a git process
may have crashed in this repository earlier:
remove the file manually to continue.

Command '['git', 'pull', 'origin', 'master']' returned non-zero exit status 128.
Traceback (most recent call last):
  File "/home/gulnara/Documents/tpcc/tpcc-course-2020/client/client.py", line 324, in main
    args.cmd(args)
  File "/home/gulnara/Documents/tpcc/tpcc-course-2020/client/client.py", line 96, in update_command
    client.update(args.all)
  File "/home/gulnara/Documents/tpcc/tpcc-course-2020/client/tpcc/course.py", line 46, in update
    subprocess.check_call(["git", "pull", "origin", "master"])
  File "/usr/lib/python3.6/subprocess.py", line 311, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['git', 'pull', 'origin', 'master']' returned non-zero exit status 128.