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

Calculating dependencies ... done!
Dependency resolution took 1.00 s (backtrack: 0/20).

[ebuild  N     ] acct-group/haproxy-0-r3::gentoo  0 KiB
[ebuild  N     ] acct-user/haproxy-0-r3::gentoo  0 KiB
[ebuild  N     ] net-proxy/haproxy-3.0.5:0/3.0::gentoo  USE="crypt net_ns pcre slz ssl threads (-51degrees) -doc -examples -lua -pcre-jit -prometheus-exporter (-systemd) -test -tools (-wurfl) -zlib" LUA_SINGLE_TARGET="-lua5-3 -lua5-4" 4588 KiB

Total: 3 packages (3 new), Size of downloads: 4588 KiB