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

Calculating dependencies ... done!
Dependency resolution took 0.99 s (backtrack: 0/20).

[ebuild  N     ] sci-physics/bullet-3.21:0/3.21::gentoo  USE="openmp threads -doc -double-precision -examples -extras (-tbb) (-test)" 129929 KiB

Total: 1 package (1 new), Size of downloads: 129929 KiB