unlike the name might suggest, proc_kill() doesn't use kill(2) so proc is not needed.

This time with a temporary variable to avoid not to trigger -Wpointer-sign, sigh.

brought to my attention by gcc who isn't smart enough to figure out that `ret' is always set.

-Wno-deprecated-declarations is needed because of OpenSSL 3 (and macos stupidly deprecating daemon(3) in favour of that trash of posix_spawn.)

now it resembles less oconfigure and more the configure scripts I'm using in my recent projects. I'd argue it's more easy to use it.

not really sold on this one, I don't see what other interpretation could be given, but it's not standard so...

the runtime tests fails on the ci (gg: Connection refused); will be revisited after we get a real `listen on' directive.

we can use cmp to tell if two files are different, which also has the benefit of being available everywhere and reporting the byte offset of the first difference. Reduces the test dependencies on some systems.

We dup(1) the ca fd and send it to various processes, so they fail loading it. Instead, use load_file to get a buffer with the file content and pass that to load_ca which then loads via BIO.