Follow-up Comment #1, bug #13600 (project freeciv):
Going slightly off topic; it's on purpose so that you can build new kind of
plant in a city that already has one. Otherwise player would be forced to
sell old one before *starting* to build new one, meaning old plant would not
be used in the process of building new one.
Reply to this item at:
Message sent via/by Gna!
Freeciv-dev mailing list