diff --git a/testsuite/config/unix.exp b/testsuite/config/unix.exp
index 522efb15..1318e9a6 100644
--- a/testsuite/config/unix.exp
+++ b/testsuite/config/unix.exp
@@ -146,3 +146,12 @@ proc kill_testproc { } {
     kill_process $testproc2_pid
     file delete $testproc_path
 }
+
+proc get_tty {} {
+    if { [catch { set raw_tty [ exec tty ] } msg]} {
+        warning "No TTY found"
+        return ""
+    }
+    regexp "/dev/(.+)" $raw_tty > tty
+    return $tty
+}
diff --git a/testsuite/pgrep.test/pgrep.exp b/testsuite/pgrep.test/pgrep.exp
index 152b6ecc..1c6cec6f 100644
--- a/testsuite/pgrep.test/pgrep.exp
+++ b/testsuite/pgrep.test/pgrep.exp
@@ -9,8 +9,7 @@ set not_uid [ expr { $uid + 1 } ]
 set gid [ exec id -g ]
 set not_gid [ expr { $gid + 1 } ] 
 set ps "${topdir}ps/pscommand"
-set raw_tty [ exec tty ]
-regexp "/dev/(.+)" $raw_tty > tty
+set tty [ get_tty ]
 
 set test "pgprep with no arguments"
 spawn $pgrep
@@ -80,8 +79,12 @@ spawn $pgrep -s 1 $testproc_comm
 expect_blank "$test"
 
 set test "pgrep matches on tty"
-spawn $pgrep -t $tty $testproc_comm
-expect_pass "$test" "^$testproc1_pid\\s+$testproc2_pid\\s*$"
+if { $tty == "" } {
+  untested "$test"
+} else {
+    spawn $pgrep -t $tty $testproc_comm
+    expect_pass "$test" "^$testproc1_pid\\s+$testproc2_pid\\s*$"
+}
 
 set test "pgrep doesn't match with bogus tty"
 spawn $pgrep -t glass $testproc_comm
diff --git a/testsuite/pkill.test/pkill.exp b/testsuite/pkill.test/pkill.exp
index 5eece7de..c583cbe9 100644
--- a/testsuite/pkill.test/pkill.exp
+++ b/testsuite/pkill.test/pkill.exp
@@ -9,8 +9,7 @@ set not_uid [ expr { $uid + 1 } ]
 set gid [ exec id -g ]
 set not_gid [ expr { $gid + 1 } ] 
 set ps "${topdir}ps/pscommand"
-set raw_tty [ exec tty ]
-regexp "/dev/(.+)" $raw_tty > tty
+set tty [ get_tty ]
 
 set test "pkill with no arguments"
 spawn $pkill
diff --git a/testsuite/ps.test/ps_output.exp b/testsuite/ps.test/ps_output.exp
index 3a6f3d86..1b2c0972 100644
--- a/testsuite/ps.test/ps_output.exp
+++ b/testsuite/ps.test/ps_output.exp
@@ -9,8 +9,6 @@ set uid [ exec id -u ]
 set not_uid [ expr { $uid + 1 } ] 
 set gid [ exec id -g ]
 set not_gid [ expr { $gid + 1 } ] 
-set raw_tty [ exec tty ]
-regexp "/dev/(.+)" $raw_tty > tty
 
 # All the fields
 # Cannot do args,cmd,comm
diff --git a/testsuite/ps.test/ps_sched_batch.exp b/testsuite/ps.test/ps_sched_batch.exp
index e0c31ffd..c58b9a26 100644
--- a/testsuite/ps.test/ps_sched_batch.exp
+++ b/testsuite/ps.test/ps_sched_batch.exp
@@ -1,12 +1,14 @@
 #
 # check the ps SCHED_BATCH scheduler policy output
 #
-set ps "${topdir}ps/pscommand"
-set schedbatch "${topdir}testsuite/test-schedbatch"
-
-spawn $schedbatch 18
-
+# This is too flaky on certain build systems to be
+# reliable - CS
+#set ps "${topdir}ps/pscommand"
+#set schedbatch "${topdir}testsuite/test-schedbatch"
+#
+#spawn $schedbatch 18
+#
 set test "ps SCHED_BATCH scheduler"
-spawn $ps --no-header -o comm,cls,nice -a
-expect_pass "$test" "\\s+test-schedbatch\\s+B\\s+18"
+#spawn $ps --no-header -o comm,cls,nice -a
+#expect_pass "$test" "\\s+test-schedbatch\\s+B\\s+18"
 untested "$test"