Bug Description
I wrote this as a package comment in my magefile.go:

// This is a magefile, to be called with `go tool mage` (github.com/magefile/mage).
package main

What did you do?
I called go tool mage.

What did you expect to happen?
Successful run.

What actually happened?
mage_output_file.go didn't compile.

Environment

$ go tool mage --version
Mage Build Tool <not set>
Build Date: <not set>
Commit: <not set>
built with: go1.26.0

(latest as of today)

Additional context
The line that breaks in mage_output_file.go is:

_fmt.Println(`This is a magefile, to be called with `go tool mage` (github.com/magefile/mage).
`)

The string needs escaping.