"JAVA_HOME is not defined correctly" while all env variables are set in jenkins

[jack]

Hey guys,

Got another mystery here... One of our projects uses java 6 (which requires ant 9); while on the linux server I installed openjdk-8 and ant 10 which work fine for all other projects. 

Then I want to install java 6 on the linux server so Jenkins master can build this project too (currently this project is built on a widnows agent for which I configured java 6 and ant 9). But when I do a "sudo apt-get install openjdk-6-jdk", ubuntu tells me :

Reading package lists... Done

Building dependency tree

Reading state information... Done

E: Unable to locate package openjdk-6-jdk

if I just do a "sudo apt-get install openjdk-6-jre", I get:

Reading package lists... Done

Building dependency tree

Reading state information... Done

Package openjdk-6-jre is not available, but is referred to by another package.

This may mean that the package is missing, has been obsoleted, or

is only available from another source

But when I went to packages.ubuntu.com and search for openjdk-6-jdk, it's there.

Then I tried to scp the working java 6 and ant 9 to the server where jenkins resides. Then when I run a job in jenkins, I get:

[Ant_test] $ ant
Error: JAVA_HOME is not defined correctly.
  We cannot execute /usr/bin/jdk-6u43-linux-x64.bin/bin/java

I have set JAVA_HOME and ANT_HOME env variables in jenkins and also in master node configs to point to older versions. Why jenkins still complains? I already gave it the correct java and ant...

If somebody knows anything on this subject, thanks very much :)