go version devel +b61b1d2c57 Sun Mar 18 16:53:53 2018 +0000 linux/amd64
package n
type R interface{S}
type S=interface{R}go build crash.go
panic: runtime error: invalid memory address or nil pointer dereference
goroutine 1 [running]:
cmd/compile/internal/gc.dowidth()
cmd/compile/internal/types.(*Type).Fields()
cmd/compile/internal/gc.expandiface()
cmd/compile/internal/gc.dowidth()
cmd/compile/internal/types.(*Type).Fields()
cmd/compile/internal/gc.expandiface()
cmd/compile/internal/gc.dowidth()
cmd/compile/internal/gc.resumecheckwidth()
cmd/compile/internal/gc.Main()
main.main()
Found with go-fuzz. #19109
go version devel +b61b1d2c57 Sun Mar 18 16:53:53 2018 +0000 linux/amd64
go build crash.go
Found with go-fuzz. #19109