I am running the same OSX El Capitan (from a non-administrator account) and I have no problems installing the ConTeXt-beta with the following script executed inside a fresk and empty directory:

#!/bin/bash
rsync -ptv rsync://contextgarden.net/minimals/setup/first-setup.sh .
chmod a+x first-setup.sh
mkdir tex
cd tex
ln -s ~/Documents/TeX/texmf texmf-local
cd ..
sh ./first-setup.sh --context=beta >first-setup.log
#sh ./first-setup.sh --context=current >first-setup.log
#sh ./first-setup.sh --context=date >first-setup.log
exit


On 26 Apr 2016, at 11:34, Mojca Miklavec <mojca.miklavec.lists@gmail.com<mailto:mojca.miklavec.lists@gmail.com>> wrote:

On 26 April 2016 at 11:21, Jaroslav Hajtmar wrote:
Hello ConTeXist
I have a problem with updating ConTeXt on my Mac OS X (El Captain). When you
run the update script to me an error message appears, which surprises me,
since I logged on as the system administrator. Can anyone advise me on what
could be the problem.

Running rsync as an administrator has an ugly consequence that you end
up copying the UID and GUID as-is, so you might end up with files
owned by very strange or perhaps even non-existing users.

Maybe you could play with
   --chown=USER:GROUP
when calling rsync from first-setup.sh to start with.

Who currently owns bin and bin/luatex?

It is not impossible that something changed yesterday though (I was
messing with the server), but the installation works for me. What
happens if you run the installation as a regular user (to a fresh
directory)?

We should look into it, but I need some proper diagnosis first.

Mojca
___________________________________________________________________________________

Hans van der Meer