when mistyping a library to upgrade, the error message could be better

[stew]

@unison/distributed/main> upgrade foo bar

  ⚠️
  
  The namespace .__projects._757ad532_adee_4961_b106_a6ca4dfd24ff.branches._d60237fa_26ac_4b9a_931d_e1d58a775ad5.lib.foo doesn't exist.

I shouldn't see the UUIDs here

[hojberg]

I can confirm that this still happens.