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

Calculating dependencies ... done!
Dependency resolution took 1.51 s (backtrack: 0/20).

[ebuild  NS    ] dev-build/autoconf-2.71-r9:2.71::gentoo [2.72-r6:2.72::gentoo] USE="-verify-sig" 1263 KiB

Total: 1 package (1 in new slot), Size of downloads: 1263 KiB