Why doesn’t `precondition(_:_:file:line:)` print the message on -O builds?

[taylorswift]

i often find myself needing something like precondition(_:_:file:line:) that prints the message on release builds. but fatalError(_:file:line:) is a bit too heavyweight because instead of

precondition(x === y, "object does not match")

it turns into

guard x === y
else
{
    fatalError("unreachable: object does not match")
}

why can’t precondition(_:_:file:line:) just print the message in release builds?

[Martin (Martin R)]

It seems that this has been discussed earlier:

What is the reason for precondition(condition:message:) to fail silently in release builds?

I literally spent 7+ hours debugging crashing web server with 132 exit code. At first I thought it's a swift-docker related problem, but then I found out in stdlib source code (and shortly after that in official documentation, lol) that precondition shows error message only in debug builds, otherwise just trap. I can't come up with any reason to do that, because obviously a) this is what precondition is made for — to do sanity checks not just in debug builds (like assert), but also in release a…

[bbrk24]

My understanding is that this is one of the main advantages to using preconditionFailure over fatalError -- not having to log out a message is not only slightly better for performance and binary size, but also more secure since it means your file names don't end up in the binary.