kpsewhich + script in Mac

[Paulo Roberto Massa Cereda]

Friends,

Apologies if this is too Mac-focused.

We recently received a report of arara not working inside TeXworks in a 
Mac machine. The 'arara' command (which is a symlink to 'arara.sh') is 
unable to locate kpsewhich and thus the arara jar is nowhere to be 
found. It was reproducible in my Mac machine as well.

Context:

https://tex.stackexchange.com/questions/512037/running-arara-from-texworks-on-a-mac

The 'culprit' line in our script is as follows:

---
jarpath=`kpsewhich --progname="$scriptname" --format=texmfscripts "$jar"`
---

kpsewhich was used to locate the proper jar file and thus set up the 
full path to be provided to the virtual machine later on:

---
exec java -jar "$jarpath" "$@"
---

I am a bit puzzled on why kpsewhich is not found. I understand this is a 
path issue situation, but my Mac knowledge is almost non-existent. I 
thought TeX paths were globally visible...

I really appreciate any comments and findings towards my unfortunate 
scenario. Thank you!

Cheerio,

Paulo