Another attempt at thoroughly fixing tmux ssh agent.

home/programs/server.nix

@@ -398,7 +398,11 @@
         setw -g automatic-rename on
         set -g set-titles on
 
-        set-environment -g 'SSH_AUTH_SOCK' $HOME/.ssh/ssh_auth_sock
+        # first, unset update-environment[SSH_AUTH_SOCK] (idx 3), to prevent
+        # the client overriding the global value
+        set-option -g -u update-environment[3]
+        # And set the global value to our static symlink'd path:
+        set-environment -g SSH_AUTH_SOCK $HOME/.ssh/ssh_auth_sock
       '';
     };
   };