New issue 851: ray object fields are out of order https://bitbucket.org/yt_analysis/yt/issue/851/ray-object-fields-are-out-of-...
Ray objects no longer return fields in order along the ray from the start to the end position. This can be seen with the following:
#!python ds = load(...) ray = ds.ray(start, end) print ray["t"]
The t values should go increase monotonically from 0 to 1, but instead are scrambled. This can be worked around with an argsort of the fields, but I think this is still a bug, or at least a regression.