I just rebuilt the latest emacs master, and found that I can no longer use
sudo in eshell.
I get the error message:
Don’t know how to make a buffer-local variable an alias:
tramp-use-connection-share

This variable was recently introduced:
https://github.com/emacs-mirror/emacs/commit/1c39347d58533280bae74c712ad0016a5c8992aa