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

Calculating dependencies ... done!
Dependency resolution took 1.08 s (backtrack: 0/20).

[ebuild  N     ] dev-db/lmdb-0.9.36:0/0.9.36::gentoo  USE="-static-libs" 147 KiB
[ebuild  N     ] acct-group/owntracks-0-r1::gentoo  0 KiB
[ebuild  N     ] acct-group/mosquitto-0-r3::gentoo  0 KiB
[ebuild  N     ] dev-libs/libconfig-1.8.2:0/15::gentoo  USE="cxx -debug -static-libs -test" 3262 KiB
[ebuild  N     ] dev-libs/cJSON-1.7.19::gentoo  USE="-test" 348 KiB
[ebuild  N     ] acct-user/owntracks-0-r1::gentoo  0 KiB
[ebuild  N     ] acct-user/mosquitto-0-r3::gentoo  0 KiB
[ebuild  N     ] app-misc/mosquitto-2.0.22::gentoo  USE="bridge persistence srv ssl -examples (-systemd) -tcpd -test -websockets" 788 KiB
[ebuild  N     ] sci-geosciences/owntracks-recorder-1.0.4::gentoo  USE="crypt http mqtt ping tours -kill -lua" LUA_SINGLE_TARGET="-lua5-3 -lua5-4" 4391 KiB

Total: 9 packages (9 new), Size of downloads: 8934 KiB