Jekyll not found - check setup requirements

[sandrobilbeisi]

Jekyll not found - check setup requirements

apparently
which -s jekyll
returns a silent failure

rbenv which jekylll
works better

Mac OS X 10.10.5
XCode 7.2.1 (7C1002)
rbenv 1.1.1
ruby 2.4.3
jekyll 3.6.2

[sandrobilbeisi]

I keep getting errors

Command /bin/sh failed with exit code 2