Cross-posted to Mathematica.SE
I have a Raspberry Pi 1B with Raspbian Buster and Wolfram Engine 12.0.1.
If I try to use J/Link, I get the following error message:
~ $ wolfram
Mathematica 12.0.1 Kernel for Linux ARM (32-bit)
Copyright 1988-2019 Wolfram Research, Inc.
Error occurred during initialization of VM
Server VM is only supported on ARMv7+ VFP
InstallJava::fail: A link to the Java runtime could not be established.
I am not using J/Link directly, but several components of Mathematica require it.
Has anyone encountered this problem, and is there a solution?
I have seen something similar when installing wolfram-engine. This could be solved by installing an older Java: https://www.raspberrypi.org/forums/viewtopic.php?t=212040 This question is not about installing wolfram-engine (which I managed to do) but about using it on a Raspberry Pi 1B.
I have the following versions of Java installed:
~ $ apt list --installed|grep jdk
WARNING: apt does not have a stable CLI interface. Use with caution in scripts.
openjdk-11-jdk-headless/stable,now 11.0.6+10-1~deb10u1 armhf [installed,automatic]
openjdk-11-jdk/stable,now 11.0.6+10-1~deb10u1 armhf [installed,automatic]
openjdk-11-jre-headless/stable,now 11.0.6+10-1~deb10u1 armhf [installed,automatic]
openjdk-11-jre/stable,now 11.0.6+10-1~deb10u1 armhf [installed,automatic]
openjdk-8-jre-headless/stable,now 8u212-b01-1+rpi1 armhf [installed,automatic]
openjdk-8-jre/stable,now 8u212-b01-1+rpi1 armhf [installed]
Trying to remove the -11 ones with apt remove would also remove wolfram-engine.
This seems to work:
Manually install opendjk-8:
sudo apt-get install openjdk-8-jre
Then, after having installed wolfram-engine (which will also install opendjk-11 and make it the default), manually choose openjdk-8 as the default:
sudo update-alternatives --config java
This will show a list of choices. Choose openjdk-8.
It seems that wolfram-engine only lists Oracle Java 8 as a valid dependency. This is no longer present in Raspbian Buster. To save users trouble, maybe it would be a good idea to allow opendjk-8 as well? Or does this have known compatibility issues?