In the odoo developer tutorial page
https://www.odoo.com/documentation/master/developer/tutorials/getting_started/02_setup.html
Section Prepare the environment
2nd headline
Clone the repository on your machine with:
git clone git@github.com:odoo/technical-training-sandbox.git
Command to clone repo will fail
due to change of different repo name therefore need different URL
from
git@github.com:odoo/technical-training-sandbox.git
now it is
git@github.com:odoo/technical-training.git
So using command below would work again.
git clone git@github.com:odoo/technical-training.git