Caution on macOS 10.12.4: sudo is broken
macperformanceguide.com> The ONLY fix that works is an erase/reinstall and manual reinstall of apps and data and reconfigure. This can take many hours for advanced users like me, with a detailed working environment.
This line bugged me a bit, surely if you're a "pro" user, you would have a set of dotfiles and a script to install things from Homebrew.
As pointed out in the article, there's probably a state problem here. I don't repro on the one 10.12.4 machine I have. What's really mystifying is that it eventually works (five minutes later), and the author states that nothing networky is involved (the example uses date command). My first guess was that sudo foobar was trying to access $FLAKEY_NETWORK_RESOURCE, but apparently not.
I don't see why some failing/timing out network resource was eliminated here. Fwiw, I'm on 10.12.4 as well and see no issues.
Would look at tcpdump or netstat (look for SYN_SENT connections) while sudo is hung. Also suggest hitting ctrl-t a few times while sudo is busy and see what is going on. Can also dtrace sudo and/or whatever dtrace shows sudo is talking to, and you'll eventually find the problem that way for sure (though you might not be able to fix it, but I suspect you will).