Getting this on running
./configure on Ubuntu 20.04 for the new 27.1 install
... checking for X... no checking for X... true configure: error: You seem to be running X, but no X development libraries were found. You should install the relevant development files for X and for the toolkit you want, such as Gtk+ or Motif. Also make sure you have development files for image handling, i.e. tiff, gif, jpeg, png and xpm. If you are sure you want Emacs compiled without X window support, pass --without-x to configure.
I've been running 26.3 just fine with X. I should have all the necessary libs from that install. What should I do here?