//golangcitest:args -Egovet //golangcitest:config linters-settings.govet.enable=ifaceassert package testdata import ( "io" ) func GovetIfaceAssert() { var v interface { Read() } _ = v.(io.Reader) // ERROR "impossible type assertion: no type can implement both interface\\{Read\\(\\)\\} and io\\.Reader \\(conflicting types for Read method\\)" }