//golangcitest:args -Egovet //golangcitest:config_path testdata/configs/govet_ifaceassert.yml package testdata import ( "io" ) func GovetIfaceAssert() { var v interface { Read() } _ = v.(io.Reader) // want "impossible type assertion: no type can implement both interface\\{Read\\(\\)\\} and io\\.Reader \\(conflicting types for Read method\\)" }