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

Calculating dependencies ... done!
Dependency resolution took 1.01 s (backtrack: 0/20).

[ebuild  N     ] dev-libs/libatomic_ops-7.10.0::gentoo  531 KiB
[ebuild  N     ] dev-libs/boehm-gc-8.2.12::gentoo  USE="large threads -cxx -static-libs" 1204 KiB
[ebuild  N     ] dev-scheme/stklos-26.0::gentoo  USE="threads" 11170 KiB

Total: 3 packages (3 new), Size of downloads: 12903 KiB