Build: #1 was successful
Job: Test Tools Many Linux 2.28 was successful
Job result summary
- Completed
- Duration
- 21 minutes
- Agent
- cbt-el7-7.cv.nrao.edu (2)
- Revision
-
299e8a4174f909ffbba6acce264ccc3d3a4e092e
- Total tests
- 696
Tests
- 696 tests in total
- 5 tests were quarantined / skipped
- 14 minutes taken in total.
Error summary
The build generated some errors. See the full build log for more details.
fatal: could not read Username for 'https://open-bitbucket.nrao.edu': No such device or address
Error response from daemon: No such container: wheel-container-test
Error response from daemon: No such container: wheel-container-test
2026-03-12 16:32:05 INFO GJonesSpline::solve() Accumulating data for: field= 1445+09900002_0, spw= 0, nchan= 63
2026-03-12 16:32:05 INFO GJonesSpline::solve() Accumulating data for: field= N5921_2, spw= 0, nchan= 63
2026-03-12 16:32:05 INFO GJonesSpline::solve() Number of timestamps in data = 60
2026-03-12 16:32:05 INFO GJonesSpline::getKnots() Gridded splinetime = 5280 sec.
2026-03-12 16:32:05 INFO GJonesSpline::solve() Number of cubic spline control points = 4
2026-03-12 16:32:05 INFO GJonesSpline::solve() Number of cubic spline knots = 8
2026-03-12 16:32:05 INFO GJonesSpline::solve() Number of cubic spline segments = 1
2026-03-12 16:32:05 INFO GJonesSpline::solve() Fitting amplitude spline.
2026-03-12 16:32:05 INFO GJonesSpline::solve() Searching for and correcting phase-wraps on each baseline.
2026-03-12 16:32:05 INFO GJonesSpline::solve() Fitting phase spline.
2026-03-12 16:32:05 INFO GJonesSpline::updateCalTable Storing solutions in table gainspline
2026-03-12 16:32:05 INFO calibrater::solve Finished solving.
2026-03-12 16:32:05 WARN calibrater::setvi(bool,bool) Forcing use of NEW VisibilityIterator.
2026-03-12 16:32:05 INFO calibrater::open ****Using NEW VI2-driven calibrater tool****
2026-03-12 16:32:05 INFO calibrater::open Opening MS: gaincaltest2.ms for calibration.
2026-03-12 16:32:05 INFO Clearing all model records in MS header.
2026-03-12 16:32:05 INFO VisSetUtil::addScrCols Adding MODEL_DATA and CORRECTED_DATA column(s).
2026-03-12 16:32:07 INFO VisSetUtil::initScrCols Initializing MODEL_DATA to (unity).
2026-03-12 16:32:07 INFO VisSetUtil::initScrCols Initialized 328860 rows.
2026-03-12 16:32:07 INFO Calibrater:: Initializing nominal selection to the whole MS.
2026-03-12 16:32:07 INFO calibrater::specifycal Beginning specifycal-----------------------
2026-03-12 16:32:07 INFO Creating G Jones table from specified parameters.
2026-03-12 16:32:07 INFO Generating 'G' corrections.
2026-03-12 16:32:07 INFO Specified parameter(s) (per spw and pol) repeated on all antennas.
2026-03-12 16:32:07 INFO Specified parameter(s) (per spw and antenna) repeated on all polarizations.
2026-03-12 16:32:07 INFO spwId=1 antId=<all> polId=<all> parameter= 3 (ip0,ip1 = [0, 0, 0],[1, 0, 9])
2026-03-12 16:32:07 INFO Writing solutions to table: testcalout.cal
2026-03-12 16:32:07 WARN calibrater::setvi(bool,bool) Already using NEW VisibilityIterator.
2026-03-12 16:32:07 WARN calibrater::setvi(bool,bool) Forcing use of OLD VisibilityIterator.
2026-03-12 16:32:07 INFO calibrater::open ****Using OLD VI-driven calibrater tool****
2026-03-12 16:32:07 INFO calibrater::open Opening MS: gaincaltest2.ms for calibration.
2026-03-12 16:32:07 INFO Clearing all model records in MS header.
2026-03-12 16:32:07 INFO VisSetUtil::addScrCols Adding MODEL_DATA and CORRECTED_DATA column(s).
2026-03-12 16:32:09 INFO VisSetUtil::initScrCols Initializing MODEL_DATA to (unity).
2026-03-12 16:32:09 INFO VisSetUtil::initScrCols Initialized 328860 rows.
2026-03-12 16:32:09 INFO Calibrater:: Initializing nominal selection to the whole MS.
2026-03-12 16:32:09 INFO calibrater::setapply Beginning setapply--(MSSelection version)-------
2026-03-12 16:32:09 INFO Calibrater::setapply(type, applypar) Arranging to APPLY:
2026-03-12 16:32:09 INFO Calibrater::setapply(type, applypar) . G Jones: table=gaincaltest2.ms.G0 select= interp=linear spwmap=[-1] calWt=false
2026-03-12 16:32:09 INFO calibrater::setsolve Beginning setsolve--(MSSelection version)-------
2026-03-12 16:32:09 INFO Calibrater::setsolve Arranging to SOLVE:
2026-03-12 16:32:09 INFO Calibrater::setsolve . Mf Mueller: table=output.ms append=false solint=inf,none refantmode='flex' refant='none' minsnr=0 apmode=AP solnorm=false
2026-03-12 16:32:09 INFO Calibrater::state The following calibration terms are arranged for apply:
2026-03-12 16:32:09 INFO Calibrater::state . G Jones: table=gaincaltest2.ms.G0 select= interp=linear spwmap=[-1] calWt=false
2026-03-12 16:32:09 INFO Calibrater::state The following calibration term is arranged for solve:
2026-03-12 16:32:09 INFO Calibrater::state . Mf Mueller: table=output.ms append=false solint=inf,none refantmode='flex' refant='none' minsnr=0 apmode=AP solnorm=false
2026-03-12 16:32:09 INFO calibrater::solve Beginning solve-----------------------------
2026-03-12 16:32:09 INFO Calibrater::solve The following calibration terms are arranged for apply:
2026-03-12 16:32:09 INFO Calibrater::solve . G Jones: table=gaincaltest2.ms.G0 select= interp=linear spwmap=[-1] calWt=false
2026-03-12 16:32:09 INFO Calibrater::solve The following calibration term is arranged for solve:
2026-03-12 16:32:09 INFO Calibrater::solve . Mf Mueller: table=output.ms append=false solint=inf,none refantmode='flex' refant='none' minsnr=0 apmode=AP solnorm=false
2026-03-12 16:32:09 INFO Solving for Mf Mueller
2026-03-12 16:32:09 INFO For solint = inf, found 84 solution intervals.
2026-03-12 16:32:11 INFO Found good Mf Mueller solutions in 84 intervals.
2026-03-12 16:32:11 INFO Writing solutions to table: output.ms
2026-03-12 16:32:11 INFO calibrater::solve Finished solving.
2026-03-12 16:32:11 WARN calibrater::setvi(bool,bool) Forcing use of NEW VisibilityIterator.
2026-03-12 16:32:11 INFO calibrater::open ****Using NEW VI2-driven calibrater tool****
2026-03-12 16:32:11 INFO calibrater::open Opening MS: gaincaltest2.ms for calibration.
2026-03-12 16:32:11 INFO Clearing all model records in MS header.
2026-03-12 16:32:11 INFO VisSetUtil::addScrCols Adding MODEL_DATA and CORRECTED_DATA column(s).
2026-03-12 16:32:13 INFO VisSetUtil::initScrCols Initializing MODEL_DATA to (unity).
2026-03-12 16:32:13 INFO VisSetUtil::initScrCols Initialized 328860 rows.
2026-03-12 16:32:13 INFO Calibrater:: Initializing nominal selection to the whole MS.
2026-03-12 16:32:13 INFO name:: No table opened.
2026-03-12 16:32:13 INFO showcache:: The Table Cache has the following 16 entries:
2026-03-12 16:32:13 INFO showcache:: 0: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms"
2026-03-12 16:32:13 INFO showcache:: 1: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/ANTENNA"
2026-03-12 16:32:13 INFO showcache:: 2: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/DATA_DESCRIPTION"
2026-03-12 16:32:13 INFO showcache:: 3: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/FEED"
2026-03-12 16:32:13 INFO showcache:: 4: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/FIELD"
2026-03-12 16:32:13 INFO showcache:: 5: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/FLAG_CMD"
2026-03-12 16:32:13 INFO showcache:: 6: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/HISTORY"
2026-03-12 16:32:13 INFO showcache:: 7: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/OBSERVATION"
2026-03-12 16:32:13 INFO showcache:: 8: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/POINTING"
2026-03-12 16:32:13 INFO showcache:: 9: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/POLARIZATION"
2026-03-12 16:32:13 INFO showcache:: 10: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/PROCESSOR"
2026-03-12 16:32:13 INFO showcache:: 11: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/SOURCE"
2026-03-12 16:32:13 INFO showcache:: 12: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/SPECTRAL_WINDOW"
2026-03-12 16:32:13 INFO showcache:: 13: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/STATE"
2026-03-12 16:32:13 INFO showcache:: 14: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/SYSCAL"
2026-03-12 16:32:13 INFO showcache:: 15: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/WEATHER"
2026-03-12 16:32:13 INFO name:: No table opened.
2026-03-12 16:32:13 INFO showcache:: The Table Cache is empty.
2026-03-12 16:32:13 WARN calibrater::setvi(bool,bool) Already using NEW VisibilityIterator.
2026-03-12 16:32:13 INFO calibrater::open ****Using NEW VI2-driven calibrater tool****
2026-03-12 16:32:13 INFO calibrater::open Opening MS: gaincaltest2.ms for calibration.
2026-03-12 16:32:13 INFO Clearing all model records in MS header.
2026-03-12 16:32:13 INFO VisSetUtil::addScrCols Adding MODEL_DATA and CORRECTED_DATA column(s).
2026-03-12 16:32:14 INFO VisSetUtil::initScrCols Initializing MODEL_DATA to (unity).
2026-03-12 16:32:15 INFO VisSetUtil::initScrCols Initialized 328860 rows.
2026-03-12 16:32:15 INFO Calibrater:: Initializing nominal selection to the whole MS.
2026-03-12 16:32:15 INFO calibrater::setapply Beginning setapply--(MSSelection version)-------
2026-03-12 16:32:15 INFO Calibrater::setapply(type, applypar) Arranging to APPLY:
2026-03-12 16:32:15 INFO Calibrater::setapply(type, applypar) . G Jones: table=gaincaltest2.ms.G0 select= interp=linear spwmap=[-1] calWt=false
2026-03-12 16:32:15 INFO calibrater::correct Beginning correct---------------------------
2026-03-12 16:32:15 INFO Calibrater::correct2 (VI2/VB2) The following calibration terms are arranged for apply:
2026-03-12 16:32:15 INFO Calibrater::correct2 (VI2/VB2) . G Jones: table=gaincaltest2.ms.G0 select= interp=linear spwmap=[-1] calWt=false
2026-03-12 16:32:18 INFO calibrater::correct Finished correcting.
2026-03-12 16:32:18 WARN calibrater::setvi(bool,bool) Already using NEW VisibilityIterator.
Error response from daemon: No such container: wheel-container-test
Error response from daemon: No such container: wheel-container-test
2026-03-12 16:32:05 INFO GJonesSpline::solve() Accumulating data for: field= 1445+09900002_0, spw= 0, nchan= 63
2026-03-12 16:32:05 INFO GJonesSpline::solve() Accumulating data for: field= N5921_2, spw= 0, nchan= 63
2026-03-12 16:32:05 INFO GJonesSpline::solve() Number of timestamps in data = 60
2026-03-12 16:32:05 INFO GJonesSpline::getKnots() Gridded splinetime = 5280 sec.
2026-03-12 16:32:05 INFO GJonesSpline::solve() Number of cubic spline control points = 4
2026-03-12 16:32:05 INFO GJonesSpline::solve() Number of cubic spline knots = 8
2026-03-12 16:32:05 INFO GJonesSpline::solve() Number of cubic spline segments = 1
2026-03-12 16:32:05 INFO GJonesSpline::solve() Fitting amplitude spline.
2026-03-12 16:32:05 INFO GJonesSpline::solve() Searching for and correcting phase-wraps on each baseline.
2026-03-12 16:32:05 INFO GJonesSpline::solve() Fitting phase spline.
2026-03-12 16:32:05 INFO GJonesSpline::updateCalTable Storing solutions in table gainspline
2026-03-12 16:32:05 INFO calibrater::solve Finished solving.
2026-03-12 16:32:05 WARN calibrater::setvi(bool,bool) Forcing use of NEW VisibilityIterator.
2026-03-12 16:32:05 INFO calibrater::open ****Using NEW VI2-driven calibrater tool****
2026-03-12 16:32:05 INFO calibrater::open Opening MS: gaincaltest2.ms for calibration.
2026-03-12 16:32:05 INFO Clearing all model records in MS header.
2026-03-12 16:32:05 INFO VisSetUtil::addScrCols Adding MODEL_DATA and CORRECTED_DATA column(s).
2026-03-12 16:32:07 INFO VisSetUtil::initScrCols Initializing MODEL_DATA to (unity).
2026-03-12 16:32:07 INFO VisSetUtil::initScrCols Initialized 328860 rows.
2026-03-12 16:32:07 INFO Calibrater:: Initializing nominal selection to the whole MS.
2026-03-12 16:32:07 INFO calibrater::specifycal Beginning specifycal-----------------------
2026-03-12 16:32:07 INFO Creating G Jones table from specified parameters.
2026-03-12 16:32:07 INFO Generating 'G' corrections.
2026-03-12 16:32:07 INFO Specified parameter(s) (per spw and pol) repeated on all antennas.
2026-03-12 16:32:07 INFO Specified parameter(s) (per spw and antenna) repeated on all polarizations.
2026-03-12 16:32:07 INFO spwId=1 antId=<all> polId=<all> parameter= 3 (ip0,ip1 = [0, 0, 0],[1, 0, 9])
2026-03-12 16:32:07 INFO Writing solutions to table: testcalout.cal
2026-03-12 16:32:07 WARN calibrater::setvi(bool,bool) Already using NEW VisibilityIterator.
2026-03-12 16:32:07 WARN calibrater::setvi(bool,bool) Forcing use of OLD VisibilityIterator.
2026-03-12 16:32:07 INFO calibrater::open ****Using OLD VI-driven calibrater tool****
2026-03-12 16:32:07 INFO calibrater::open Opening MS: gaincaltest2.ms for calibration.
2026-03-12 16:32:07 INFO Clearing all model records in MS header.
2026-03-12 16:32:07 INFO VisSetUtil::addScrCols Adding MODEL_DATA and CORRECTED_DATA column(s).
2026-03-12 16:32:09 INFO VisSetUtil::initScrCols Initializing MODEL_DATA to (unity).
2026-03-12 16:32:09 INFO VisSetUtil::initScrCols Initialized 328860 rows.
2026-03-12 16:32:09 INFO Calibrater:: Initializing nominal selection to the whole MS.
2026-03-12 16:32:09 INFO calibrater::setapply Beginning setapply--(MSSelection version)-------
2026-03-12 16:32:09 INFO Calibrater::setapply(type, applypar) Arranging to APPLY:
2026-03-12 16:32:09 INFO Calibrater::setapply(type, applypar) . G Jones: table=gaincaltest2.ms.G0 select= interp=linear spwmap=[-1] calWt=false
2026-03-12 16:32:09 INFO calibrater::setsolve Beginning setsolve--(MSSelection version)-------
2026-03-12 16:32:09 INFO Calibrater::setsolve Arranging to SOLVE:
2026-03-12 16:32:09 INFO Calibrater::setsolve . Mf Mueller: table=output.ms append=false solint=inf,none refantmode='flex' refant='none' minsnr=0 apmode=AP solnorm=false
2026-03-12 16:32:09 INFO Calibrater::state The following calibration terms are arranged for apply:
2026-03-12 16:32:09 INFO Calibrater::state . G Jones: table=gaincaltest2.ms.G0 select= interp=linear spwmap=[-1] calWt=false
2026-03-12 16:32:09 INFO Calibrater::state The following calibration term is arranged for solve:
2026-03-12 16:32:09 INFO Calibrater::state . Mf Mueller: table=output.ms append=false solint=inf,none refantmode='flex' refant='none' minsnr=0 apmode=AP solnorm=false
2026-03-12 16:32:09 INFO calibrater::solve Beginning solve-----------------------------
2026-03-12 16:32:09 INFO Calibrater::solve The following calibration terms are arranged for apply:
2026-03-12 16:32:09 INFO Calibrater::solve . G Jones: table=gaincaltest2.ms.G0 select= interp=linear spwmap=[-1] calWt=false
2026-03-12 16:32:09 INFO Calibrater::solve The following calibration term is arranged for solve:
2026-03-12 16:32:09 INFO Calibrater::solve . Mf Mueller: table=output.ms append=false solint=inf,none refantmode='flex' refant='none' minsnr=0 apmode=AP solnorm=false
2026-03-12 16:32:09 INFO Solving for Mf Mueller
2026-03-12 16:32:09 INFO For solint = inf, found 84 solution intervals.
2026-03-12 16:32:11 INFO Found good Mf Mueller solutions in 84 intervals.
2026-03-12 16:32:11 INFO Writing solutions to table: output.ms
2026-03-12 16:32:11 INFO calibrater::solve Finished solving.
2026-03-12 16:32:11 WARN calibrater::setvi(bool,bool) Forcing use of NEW VisibilityIterator.
2026-03-12 16:32:11 INFO calibrater::open ****Using NEW VI2-driven calibrater tool****
2026-03-12 16:32:11 INFO calibrater::open Opening MS: gaincaltest2.ms for calibration.
2026-03-12 16:32:11 INFO Clearing all model records in MS header.
2026-03-12 16:32:11 INFO VisSetUtil::addScrCols Adding MODEL_DATA and CORRECTED_DATA column(s).
2026-03-12 16:32:13 INFO VisSetUtil::initScrCols Initializing MODEL_DATA to (unity).
2026-03-12 16:32:13 INFO VisSetUtil::initScrCols Initialized 328860 rows.
2026-03-12 16:32:13 INFO Calibrater:: Initializing nominal selection to the whole MS.
2026-03-12 16:32:13 INFO name:: No table opened.
2026-03-12 16:32:13 INFO showcache:: The Table Cache has the following 16 entries:
2026-03-12 16:32:13 INFO showcache:: 0: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms"
2026-03-12 16:32:13 INFO showcache:: 1: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/ANTENNA"
2026-03-12 16:32:13 INFO showcache:: 2: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/DATA_DESCRIPTION"
2026-03-12 16:32:13 INFO showcache:: 3: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/FEED"
2026-03-12 16:32:13 INFO showcache:: 4: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/FIELD"
2026-03-12 16:32:13 INFO showcache:: 5: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/FLAG_CMD"
2026-03-12 16:32:13 INFO showcache:: 6: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/HISTORY"
2026-03-12 16:32:13 INFO showcache:: 7: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/OBSERVATION"
2026-03-12 16:32:13 INFO showcache:: 8: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/POINTING"
2026-03-12 16:32:13 INFO showcache:: 9: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/POLARIZATION"
2026-03-12 16:32:13 INFO showcache:: 10: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/PROCESSOR"
2026-03-12 16:32:13 INFO showcache:: 11: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/SOURCE"
2026-03-12 16:32:13 INFO showcache:: 12: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/SPECTRAL_WINDOW"
2026-03-12 16:32:13 INFO showcache:: 13: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/STATE"
2026-03-12 16:32:13 INFO showcache:: 14: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/SYSCAL"
2026-03-12 16:32:13 INFO showcache:: 15: "/home/casatest/casa6/casatestutils/nosedir/test_tool_calibrater/gaincaltest2.ms/WEATHER"
2026-03-12 16:32:13 INFO name:: No table opened.
2026-03-12 16:32:13 INFO showcache:: The Table Cache is empty.
2026-03-12 16:32:13 WARN calibrater::setvi(bool,bool) Already using NEW VisibilityIterator.
2026-03-12 16:32:13 INFO calibrater::open ****Using NEW VI2-driven calibrater tool****
2026-03-12 16:32:13 INFO calibrater::open Opening MS: gaincaltest2.ms for calibration.
2026-03-12 16:32:13 INFO Clearing all model records in MS header.
2026-03-12 16:32:13 INFO VisSetUtil::addScrCols Adding MODEL_DATA and CORRECTED_DATA column(s).
2026-03-12 16:32:14 INFO VisSetUtil::initScrCols Initializing MODEL_DATA to (unity).
2026-03-12 16:32:15 INFO VisSetUtil::initScrCols Initialized 328860 rows.
2026-03-12 16:32:15 INFO Calibrater:: Initializing nominal selection to the whole MS.
2026-03-12 16:32:15 INFO calibrater::setapply Beginning setapply--(MSSelection version)-------
2026-03-12 16:32:15 INFO Calibrater::setapply(type, applypar) Arranging to APPLY:
2026-03-12 16:32:15 INFO Calibrater::setapply(type, applypar) . G Jones: table=gaincaltest2.ms.G0 select= interp=linear spwmap=[-1] calWt=false
2026-03-12 16:32:15 INFO calibrater::correct Beginning correct---------------------------
2026-03-12 16:32:15 INFO Calibrater::correct2 (VI2/VB2) The following calibration terms are arranged for apply:
2026-03-12 16:32:15 INFO Calibrater::correct2 (VI2/VB2) . G Jones: table=gaincaltest2.ms.G0 select= interp=linear spwmap=[-1] calWt=false
2026-03-12 16:32:18 INFO calibrater::correct Finished correcting.
2026-03-12 16:32:18 WARN calibrater::setvi(bool,bool) Already using NEW VisibilityIterator.