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

Calculating dependencies ... done!
Dependency resolution took 1.53 s (backtrack: 0/20).

[ebuild     U  ] dev-build/gtk-doc-am-1.36.1::gentoo [1.34.0::gentoo] 581 KiB

Total: 1 package (1 upgrade), Size of downloads: 581 KiB