I found that osx-env-sync was not working on Big Sur. After investigation I discovered that the launch agent was no longer in ~/Library/LaunchAgents. I copied it there using the curl command given in README.md and it works again. I don't know when the launch agent was removed except that I did not do it. It is possible it was removed when I installed Catalina as I haven't needed sync'ing for a while.
This is a note to hopefully help others.
I found that osx-env-sync was not working on Big Sur. After investigation I discovered that the launch agent was no longer in
~/Library/LaunchAgents. I copied it there using the curl command given in README.md and it works again. I don't know when the launch agent was removed except that I did not do it. It is possible it was removed when I installed Catalina as I haven't needed sync'ing for a while.