! go test testdep/p1
stderr 'package testdep/p1 \(test\)\n\timports testdep/p2\n\timports testdep/p3: build constraints exclude all Go files ' # check for full import stack

-- testdep/p1/p1.go --
package p1
-- testdep/p1/p1_test.go --
package p1

import _ "testdep/p2"
-- testdep/p2/p2.go --
package p2

import _ "testdep/p3"
-- testdep/p3/p3.go --
// +build ignore

package ignored
