Specifically this line
export CFLAGS="-O2 --fvisibility=hidden"
On https://docs.phalcon.io/en/3.2/installation
The -- dash on the fvisibility will break a compile. No such option. Should be
export CFLAGS="-O2 -fvisibility=hidden"
Only noticed it because it wasn't something I needed to learn so I was copy pasting. Someone who might know PHP but has no clue how to write or compile C will hit this and it will be a game breaker. Fortunately I know C intimately and am learning php and php frameworks. So I immediately noticed the issue.
I realize with 100% open source there's PROBABLY some way for me to edit this myself. However. I am new here as of today so please don't flame me for just reporting it for someone else to handle this time.