Issue on new craft (craftcms3) setups: vendor Twig can't read system variable
I've looked all over for a solution to this but couldn't find anything. I don't know if you've already fixed your problem now, but in case you haven't or someone else has found this error and arrived here, a simple fix for it is to add the missing information into the project.yaml in config/project/.
For my local development build, I used the following:
system:
  edition: solo
  live: true
  name: '{YOUR PROJECT NAME HERE}'
  retryDuration: null
  schemaVersion: 3.5.13
  timeZone: UTC

For the schemaVersion, it will need to match the one specified in the installed version of Craft in your vendor folder. This can also be found in the repo.
I'm not sure what the cause of the missing info is, but I am also on a Mac running Big Sur so it may be related. Once you have added in this information, you should be able to edit it normally from Settings -&gt; General.