lem.Run output question

[yerden]

Hello,

Here's an example (of meaningless) code:

package main

import (
	"bytes"
	"testing"

	"github.com/akutz/lem"
)

func copyWithBuffer(data []byte) []byte {
	//b := &bytes.Buffer{} // lem.World.m=&bytes.Buffer{} does not escape
	b := &bytes.Buffer{} // lem.World.m=does not escape
	b.Write(data)
	return b.Bytes()
}

func TestLem(t *testing.T) {
	lem.Run(t)
}

Output:

--- FAIL: TestLem (0.26s)
    --- FAIL: TestLem/World (0.00s)
        tree.go:148: error: build optimization
            reason: not found
            regexp: (?m)^.*lem_test.go:12:\d+: does not escape$
            source: 	b.Write(data)

FAIL
exit status 1
FAIL	lem_test	0.265s

Could you please explain the meaning of each output line? My guess is:

• reason is the cause of the test failure. Any other reasons possible?
• regexp was used to match the specified m. Is it possible to match not the exact line (as in commented out line 11) but a part of it, like .*does not escape.*. EDIT: sorry, I just checked, it is indeed possible :)
• source is the source code reference? why does it reference the next line then?