Seems ps (shell script from hell) uses plan9port sort. And coreutils sort do not undarstand +1 parameter. 

Try to place plan9port path before any other.

2017-04-11 9:54 GMT+03:00 Bruce Ellis <bruce.ellis@gmail.com>:
using plan9ports' "ps -e" does not print all processes. dirread /proc fun I guess.

brucee




--
С наилучшими пожеланиями
Жилкин Сергей
With best regards
Zhilkin Sergey