If no, what's the problem with using a GNU extension on
an essentially GNU system?
I could envision someone using busybox "sort" and I don't know if
that is then working ok.
But that is an unsupported setup and overall my main point has been
that I don't want to decide on a "sort | uniq" -> "sort -u"
transition.
More important would be to get some awk/grep lines into a form that
people feel is well supportable as well as being fast enough and sane.
greetings,
Florian La Roche