Steps to reproduce

package main

import "fmt"

func main() {
    n1 := float32(1.3167616e+07)
    fmt.Printf("%#v\n", n1)
}

Expected output

float32(1.3167616e+07)

Actual output

1.3167616e+07

Notes

An important property implied by the documentation for %#v is that I can copy-paste the output into a Go program to recreate that value (at least for serializable values, e.g. not functions). At least, the function should be injective.

This is not true for numerics, since the output drops the dynamic type information. When I take the actual output above and put it in a new Go program, it gets assigned a different dynamic type:

package main

import "fmt"
import "reflect"

func main() {
    n := 1.3167616e+07  // the output of `%#v`
    fmt.Printf("%s\n", reflect.TypeOf(n).String())
}

which prints:

float64

This has cost me significant debugging time. The %#v verb should print out everything about the value that I need to know.