On Wed, Aug 10, 2016 at 10:26 AM, Jose Luis Arellano <jose.4rellano@gmail.com> wrote:
This:

~/context$ ls -l $HOME/context/bin
total 8372
-rwxr-xr-x 1 pepe pepe 7982820 Aug  6 01:56 luatex*
-rw-r--r-- 1 pepe pepe   27110 Oct  6  2015 mtx-update.lua
-rwxr-xr-x 1 pepe pepe  558052 Aug  9 16:00 mtxrun*
lrwxrwxrwx 1 pepe pepe       6 Jul 26  2014 texlua -> luatex*



On the top of first-setup.sh there is 

#!/bin/sh

# Takes the same arguments as mtx-update

# you may change this if you want ...
CONTEXTROOT="$PWD/tex"

and some lines from the bottom 
env PATH="$PWD/bin:$CONTEXTROOT/texmf-$platform/bin:$PATH"


On my linux box I see, given that I'm installing under /opt/luatex/standalone-mkiv-test,
$ export|grep PWD
declare -x PWD="/opt/luatex/standalone-mkiv-test"


Perhaps your box doesn't  set PWD correctly ?


--
luigi