ShellUTest randomly fails

test log:

18/30 Test #12: ShellUTest .......................***Failed  118.91 sec
Running cxxtest tests (5 tests)opencog> Entering scheme shell; use ^D or a single . on a line by itself to exit.
guile> (ConceptNode "42")

guile> 
guile> opencog> Entering scheme shell; use ^D or a single . on a line by itself to exit.
guile> opencog> Exiting the shell
4
guile> opencog> opencog> Entering scheme shell; use ^D or a single . on a line by itself to exit.
guile> (ConceptNode "42")

guile> 
guile> opencog> Entering scheme shell; use ^D or a single . on a line by itself to exit.
guile> opencog> Exiting the shell
4
guile> opencog> Listening on port 17333
.opencog> Entering scheme shell; use ^D or a single . on a line by itself to exit.
guile> guile> opencog> Entering scheme shell; use ^D or a single . on a line by itself to exit.
guile> guile> opencog> Entering scheme shell; use ^D or a single . on a line by itself to exit.
guile> guile> Backtrace:
           8 (apply-smob/1 #<catch-closure 7f18fc09b680>)
           7 (apply-smob/1 #<catch-closure 7f18fc09d560>)
In ice-9/boot-9.scm:
   2312:4  6 (save-module-excursion #<procedure 7f18fc09f940 at ice-…>)
In ice-9/eval-string.scm:
     38:6  5 (read-and-eval #<input: string 7f18f4df3ee0> #:lang _)
In unknown file:
           4 (sleep 41)
Exception thrown while printing backtrace:
In procedure cdr: Wrong type argument in position 1 (expecting pair): ()

ERROR: In procedure apply-smob/1:
In procedure SchemeEval::interrupt: User interrupt from keyboard
ABORT: user-interrupt
Listening on port 17333
Elapsed: 0
First elapsed: 0
Second elapsed: 0
.Listening on port 17333
Received 205 bytes: opencog> Entering scheme shell; use ^D or a single . on a line by itself to exit.
guile> (ConceptNode "B")
(ConceptNode "C")
(ConceptNode "A")

guile> 
.Listening on port 17333

In ShellUTest::testMessaging:
/ws/opencog/build/tests/server/../../../tests/server/ShellUTest.cxxtest:76: Error: Expected (281 <= reso.size()), found (281 > 125)
Error: Create rep 28 of 30 in thread 11 failed
    Got: 125 >>>opencog> Entering scheme shell; use ^D or a single . on a line by itself to exit.
guile> <<<
Listening on port 17333
.
Failed 1 and Skipped 0 of 5 tests
Success rate: 80%
singnet / opencog

ShellUTest randomly fails #72
