capture: fix FDCapture.__repr__ without targetfd_save

src/_pytest/capture.py

@@ -539,7 +539,10 @@ class FDCaptureBinary(object):
             self.tmpfile_fd = tmpfile.fileno()
 
     def __repr__(self):
-        return "<FDCapture %s oldfd=%s>" % (self.targetfd, self.targetfd_save)
+        return "<FDCapture %s oldfd=%s>" % (
+            self.targetfd,
+            getattr(self, "targetfd_save", None),
+        )
 
     def start(self):
         """ Start capturing on targetfd using memorized tmpfile. """

testing/test_capture.py

@@ -1231,20 +1231,27 @@ class TestStdCaptureFDinvalidFD(object):
             """
             import os
             from _pytest import capture
+
             def StdCaptureFD(out=True, err=True, in_=True):
                 return capture.MultiCapture(out, err, in_,
-                                              Capture=capture.FDCapture)
+                                            Capture=capture.FDCapture)
+
             def test_stdout():
                 os.close(1)
                 cap = StdCaptureFD(out=True, err=False, in_=False)
+                assert repr(cap.out) == "<FDCapture 1 oldfd=None>"
                 cap.stop_capturing()
+
             def test_stderr():
                 os.close(2)
                 cap = StdCaptureFD(out=False, err=True, in_=False)
+                assert repr(cap.err) == "<FDCapture 2 oldfd=None>"
                 cap.stop_capturing()
+
             def test_stdin():
                 os.close(0)
                 cap = StdCaptureFD(out=False, err=False, in_=True)
+                assert repr(cap.in_) == "<FDCapture 0 oldfd=None>"
                 cap.stop_capturing()
         """
         )