I have a bit more debugging output on this:

./waf configure -d optimized --enable-tests --enable-modules=lte --disable-python
./test.py -s lte-tta-ff-mac-scheduler

FAIL: Test Suite "lte-tta-ff-mac-scheduler" (2.840)
PASS: Test Suite "1 UEs, distance 0 m" (0.150)
PASS: Test Suite "3 UEs, distance 0 m" (0.240)
PASS: Test Suite "6 UEs, distance 0 m" (0.360)
PASS: Test Suite "12 UEs, distance 0 m" (0.780)
PASS: Test Suite "15 UEs, distance 0 m" (0.990)
PASS: Test Suite "1 UEs, distance 3000 m" (0.110)
FAIL: Test Suite "3 UEs, distance 3000 m" (0.210)
    Details:
      Message:    Invalid Throughput!
      Condition: (double)dlDataRxed.at (i) / simulationTime (actual) < m_thrRefDl (limit) + m_thrRefDl * tolerance (tol) && (double)dlDataRxed.at (i) / simulationTime (actual) > m_thrRefDl (limit) - m_thrRefDl * tolerance (tol)
      Actual:    405
      Limit:     1.383e+06 +- 138300
      File:      ../src/lte/test/lte-test-tta-ff-mac-scheduler.cc
      Line:      282

This does not show up in debug builds.

This is probably due to Dizhi's patch to clear uninitialized variable warnings for optimized builds.  Perhaps some behavior was inadvertently changed.

(In reply to comment #1)
> I have a bit more debugging output on this:
> 
> ./waf configure -d optimized --enable-tests --enable-modules=lte
> --disable-python
> ./test.py -s lte-tta-ff-mac-scheduler
> 

I should have specified that to get the output I posted, I needed to run:

./test.py -s lte-tta-ff-mac-scheduler -t out.txt

fixed in changeset 495189af3137