Also if you wish to update OpenLane2 for caravel user project you should modify the following file https://github.com/efabless/caravel_user_project_ol2/blob/a9dd629af92482842ddcaba8d95c298b41c1895b/openlane/shell.nix#L16. In a very similar way to these instructions https://openlane2.readthedocs.io/en/latest/contributors/updating_tools.html#changing-version-info