Hi! First of all, thanks for maintaining GNU sort! I use it very often and love its performance.
Today I spent some time debugging and realized that my bug was caused by a wrong GNU invocation ("sort -k1,1 -t," instead of "sort -t, -k1,1"). Could sort warn when -t is effectively a no-op because it was specified after last -k? I know that `find` warns the user if arguments are in a wrong order, perhaps it would make sense to add it here as well? (I read FAQ/list of gotchas, but believe that my case is a bit different compared to the ones listed there) Cheers, d33tah