These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 0.97 s (backtrack: 0/20).

[ebuild  N     ] gui-apps/foot-terminfo-1.21.0::gentoo  590 KiB
[blocks B      ] >=sys-libs/ncurses-6.3[-minimal] (">=sys-libs/ncurses-6.3[-minimal]" is soft blocking gui-apps/foot-terminfo-1.21.0)

Total: 1 package (1 new), Size of downloads: 590 KiB
Conflict: 1 block (1 unsatisfied)

 * Error: The above package list contains packages which cannot be
 * installed at the same time on the same system.

  (gui-apps/foot-terminfo-1.21.0:0/0::gentoo, ebuild scheduled for merge) pulled in by
    =gui-apps/foot-terminfo-1.21.0


For more information about Blocked Packages, please refer to the following
section of the Gentoo Linux x86 Handbook (architecture is irrelevant):

https://wiki.gentoo.org/wiki/Handbook:X86/Working/Portage#Blocked_packages