Error message upgrading from 2.3.3 to 2.3.4

hi,

I tried to upgrade the 2.3.3 to latest version following instructions at: Upgrade — Indico 2.3.4 documentation

but got following error messages:
please help me how to resolve this error

thanks

Requirement already up-to-date: python-editor>=0.3 in ./.venv/lib/python2.7/site-packages (from alembic==1.4.2->indico)
Cache entry deserialization failed, entry ignored
Collecting decorator (from ipython<6,>=5.4.1->indico)
  Downloading https://files.pythonhosted.org/packages/71/bd/042e63027bea950da4e6f5545eb59b973868da854ab30a18128d3b884104/decorator-5.0.2.tar.gz
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-Hq6uj8/decorator/setup.py", line 4, in <module>
        exec(open('src/decorator.py').read(), dic)  # extract the __version__
      File "<string>", line 162
        print('Error in generated code:', file=sys.stderr)
                                              ^
    SyntaxError: invalid syntax

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-Hq6uj8/decorator/

Your pip is extremely outdated and does not understand yanked packages. Update it first using pip install -U pip setuptools

(.venv) [indico@localhost ~]$ python --version
Python 2.7.5
(.venv) [indico@localhost ~]$ python3 --version
-bash: python3: command not found
(.venv) [indico@localhost ~]$ pip --version
pip 9.0.1 from /opt/indico/.venv/lib/python2.7/site-packages (python 2.7)

and within the .env it show other version of pip

(.venv) [indico@localhost ~]$ pip install -U pip setuptools
Requirement already up-to-date: pip in ./.venv/lib/python2.7/site-packages
Requirement already up-to-date: setuptools in ./.venv/lib/python2.7/site-packages
You are using pip version 20.3.4, however version 21.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.

That’s normal, 21.x requires Python 3. In any case, 20.x is perfectly fine, and should be able to correctly install the latest indico version without issues.

pip is confusing me looking at this it says version is 9.0.1 but when issued update command it says it is up to date and 20.3.4.

[indico@localhost ~]$ source ~/.venv/bin/activate
(.venv) [indico@localhost ~]$ pip --version
pip 9.0.1 from /opt/indico/.venv/lib/python2.7/site-packages (python 2.7)
(.venv) [indico@localhost ~]$ pip install -U pip
Requirement already up-to-date: pip in ./.venv/lib/python2.7/site-packages
You are using pip version 20.3.4, however version 21.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
(.venv) [indico@localhost ~]$

Very strange… maybe try starting with a fresh virtualenv and update pip+setuptools in there as the very first thing

pip install --upgrade pip --force
did the trick, now it shows
(.venv) [indico@localhost ~]$ pip --version
pip 20.3.4 from /opt/indico/.venv/lib/python2.7/site-packages/pip (python 2.7)

Thanks you so much @ThiefMaster, now my production is updated to v2.3.4.