Plan 9 from Bell Labs’s /usr/web/sources/contrib/stallion/root/arm/go/src/cmd/vet/testdata/copylock/copylock.go
package copylock import "sync" func BadFunc() { var x *sync.Mutex p := x var y sync.Mutex p = &y *p = *x // ERROR "assignment copies lock value to \*p: sync.Mutex" }