Looking at the build failure for the nix package on darwin I noticed that explicit_bzero is used by recallocarray but not included in the compat layer...

instead of defining macros in compat.h. It's clearer that it's only for libevent2 this way

on libevent2 we need to wrap evbuffer_add with evbuffer_freeze/evbuffer_unfreeze. Not sure exactly why, probably because we're doing some evbuffer_enable/disable/enable-again. Retain compatibility with the custom libevent1 in base on OpenBSD.

i.e. trasform XYZ bytes to something readable

found by cage_: thanks!