Last night, I migrated my MacBook's operating system from 10.10 "Yosemite" to 10.11 "El Capitan". Everything seemed to go smoothly. Happily, regarding my TeX-related work, I am able to use the GUI front ends "TeXworks" and "TeXshop" just fine since completing the OS upgrade. I use MacTeX2015, with all the latest updates installed.
Oddly, though, since completing the upgrade I can no longer run any MacTeX command-line utilities such as
kpsewhich. (Actually, as I just discovered, I can no longer run
pdflatex either from a command line. However, I never do run
pdflatex from a command line prompt, so that's not an urgent problem for me -- at least not for now.)
The suggestions given in the posting Mavericks upgrade screwed up my pdflatex (command not found) do not seem to be applicable to this case, as they all seem to revolve around setting up
/usr/texbin correctly --
/usr/texbin is no longer allowed under MacOSX 10.11. The document MacTEX-2015 and El Capitan by Herb Schulz deals in depth with adjusting settings in the GUI front ends, but it appears not to touch on what to do about
/usr/texbin, which appears to be the now-missing link to TeX's command line utilities.
Pointers and solutions most welcome!