Unable to launch IDE - missing Java?

Hi, I'm not sure if this is the best place to ask but with the site having some problems, I can't download the IDE so I've resorted to building it from the source on Github:

I've followed the directions there (MacOSX Catalina) and it builds fine - I get the executable etc, but running it just gives me an alert - "Error loading JAVA".

I installed JDK1.8 per the build directions. Version info comes back as

$> java --version

openjdk version "15.0.1" 2020-10-20

OpenJDK Runtime Environment (build 15.0.1+9)

OpenJDK 64-Bit Server VM (build 15.0.1+9, mixed mode, sharing)

I'm not sure where to go from here -- has anyone encountered this?
thanks,
Chris

I do not know if this will help or not so here gos. I run Linux Mint 20 and when I launch Arduino IDE it flashes and goes away. Originally I got a lot of Java messages but they quit when I reverted back the earlier version of Python. It was looking for the printf() library from python. I eventually figured out it was installed as root, not normally accessible to standard users. So far I have not been able to download and install the IDE as a user.

To serve as a reference for others who might have the same issue and find this post, I’ll link to @oobi’s report of this in the Arduino IDE issue tracker:

gilshultz:
Originally I got a lot of Java messages but they quit when I reverted back the earlier version of Python. It was looking for the printf() library from python.

This is very strange. As far as I know, the Arduino IDE does not make any direct use of Python. It is a Java application.

Some of the 3rd party boards platforms (most prominently ESP8266 and ESP32) do use Python as part of their toolchain, and this causes a good deal of troubles since they expect the user to have the right version of Python and/or package dependencies pre-installed, whereas we are accustomed to boards platforms providing all their tools dependencies (e.g., avr-gcc, AVRDUDE) when they are installed. But I can’t imagine a situation where a missing platform tool dependency would cause the IDE to not start.

Do you have any custom IDE plugins installed (e.g., ESP Exception Decoder)? I don’t know much about those, but I suppose it is possible one could have a dependency on Python and do something at IDE startup.