RuntimeError: Exception: Unable to open image tst3.psf.
... thrown by static casa::ITUPLE casa::ImageFactory::fromFile(const casa6core::String &, casa6core::Bool) at File: src/code/imageanalysis/ImageAnalysis/ImageFactory2.cc, line: 289
test_task_tclean.py:370: in test_onefield_weighting
    report3=self.th.checkall(ret=ret, peakres=0.263, modflux=0.575, iterdone=10, imgexist=[self.img+'3.psf', self.img+'3.residual', self.img+'3.image', self.img+'3.model'], imgval=[(self.img+'3.psf',1.0,[50,50,0,0])])
../../../../casa6testenv/lib/python3.6/site-packages/casatestutils/imagerhelpers/imagetesthelpers.py:1115: in checkall
    pstr += TestHelpers().check_imval(imgval, epsilon=epsilon)
../../../../casa6testenv/lib/python3.6/site-packages/casatestutils/imagerhelpers/imagetesthelpers.py:963: in check_imval
    pstr += TestHelpers().check_pix_val(ii[0], ii[1], ii[2], epsilon=epsilon)
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