V4 To V5 Update Error

erpnext4@erpnext4ubuntu:~/frappe-bench$ bench update
remote: Counting objects: 15, done.
remote: Total 15 (delta 11), reused 11 (delta 11), pack-reused 4
Unpacking objects: 100% (15/15), done.
From https://github.com/frappe/bench
9e7248d…b682eb0 master -> origin/master

  • [new branch] bench-admin -> origin/bench-admin
    Updating 9e7248d…b682eb0
    Fast-forward
    README.md | 9 +++++++++
    bench/release.py | 2 ±
    2 files changed, 10 insertions(+), 1 deletion(-)
    remote: Counting objects: 305, done.
    remote: Compressing objects: 100% (42/42), done.
    remote: Total 305 (delta 189), reused 177 (delta 173), pack-reused 89
    Receiving objects: 100% (305/305), 77.14 KiB | 0 bytes/s, done.
    Resolving deltas: 100% (208/208), completed with 68 local objects.
    From https://github.com/frappe/frappe
    265dbd1…c54724a develop -> upstream/develop
    265dbd1…9f155d9 master -> upstream/master
  • [new tag] v5.0.33 -> v5.0.33
  • [new tag] v5.0.29 -> v5.0.29
  • [new tag] v5.0.30 -> v5.0.30
  • [new tag] v5.0.31 -> v5.0.31
  • [new tag] v5.0.32 -> v5.0.32
    Traceback (most recent call last):
    File “/usr/local/bin/bench”, line 9, in
    load_entry_point(‘bench==0.1’, ‘console_scripts’, ‘bench’)()
    File “/home/erpnext4/bench-repo/bench/cli.py”, line 56, in cli
    bench()
    File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 664, in call
    return self.main(*args, **kwargs)
    File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 644, in main
    rv = self.invoke(ctx)
    File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 991, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
    File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 837, in invoke
    return ctx.invoke(self.callback, **ctx.params)
    File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 464, in invoke
    return callback(*args, **kwargs)
    File “/home/erpnext4/bench-repo/bench/cli.py”, line 221, in update
    version_upgrade = is_version_upgrade()
    File “/home/erpnext4/bench-repo/bench/app.py”, line 98, in is_version_upgrade
    upstream_version = get_upstream_version(frappe_dir, branch=branch)
    File “/home/erpnext4/bench-repo/bench/app.py”, line 131, in get_upstream_version
    branch = get_current_branch(repo_dir)
    File “/home/erpnext4/bench-repo/bench/app.py”, line 120, in get_current_branch
    return get_cmd_output(“basename $(git symbolic-ref -q HEAD)”, cwd=repo_dir)
    File “/home/erpnext4/bench-repo/bench/utils.py”, line 257, in get_cmd_output
    return subprocess.check_output(cmd, cwd=cwd, shell=True, stderr=open(os.devnull, ‘wb’)).strip()
    File “/usr/lib/python2.7/subprocess.py”, line 573, in check_output
    raise CalledProcessError(retcode, cmd, output=output)
    subprocess.CalledProcessError: Command ‘basename $(git symbolic-ref -q HEAD)’ returned non-zero exit status 1