Screen fails with a
CANNOT I_PUSH ptem /dev/pts/4 Invalid argument

unless the following patch is applied:

--- screen-3.7.6/window.c-pp    Wed Nov 18 22:19:47 1998
+++ screen-3.7.6/window.c       Fri Mar  5 13:03:21 1999
@@ -622,7 +622,7 @@
       if (newfd >= 0)
        {
          struct mode fakemode, *modep;
-#if defined(SVR4) && !defined(sgi) && !defined(M_UNIX)
+#if defined(SVR4) && !defined(sgi) && !defined(M_UNIX) &&
!defined(linux)
          if (ioctl(newfd, I_PUSH, "ptem"))
            {
              SendErrorMsg("Cannot I_PUSH ptem %s %s", ttyn,
strerror(errno));