You probably have more than one Python installation, and it somehow takes the one where lxml is not installed. You can test it using a virtual environment, if it works then you need to verify the paths.

Hi,

You need to install Python's header files to compile lxml. try this

apt-get install python-dev libxml2 libxml2-dev libxslt-dev

and then

sudo apt-get install python3-lxml

thank you for your response.

I already did, right now I have lxml 4.9.2 and python 3.11.2. 

I tried on 5.2 and 3.12 but still same error.

Hello, 

You can try this one. 

Comment on the following dependency in the requirement.txt file 

#gevent==21.8.0 ; python_version == '3.10' # (Jammy)

#gevent==22.10.2; python_version > '3.10'

After adding this

gevent

After run 

pip3 install -r odoo/requirements.txt

Thanks.