log.Fatalf is mis-documented?

[FGasper (Felipe Gasper)]

I noticed that Mage (magefile.org) appears to set the default logger (i.e., log.Default()’s return) to discard. This is its default behaviour; to change it you have to set Mage to “verbose” mode.

I was confused on this for a while because of this:

> go doc log.Fatalf
package log // import "log"

func Fatalf(format string, v ...any)
    Fatalf is equivalent to Printf() followed by a call to os.Exit(1).

In my case that wasn’t true, which confused multiple folks on my team.

Should this documentation be updated, or am I missing something? I’m thinking:

Fatalf is like fmt.Printf() followed by a call to os.Exit(1). Unlike Printf, though, Fatalf’s output goes to the standard logger’s output, which may or may not be os.Stdout.

[skillian (Sean Killian)]

The documentation doesn’t say it behaves like fmt.Printf. It says it behaves like Printf (i.e. log.Printf), which behaves as you described it.

[FGasper (Felipe Gasper)]

Ahh, ok. Thank you for clarifying.