Bugzilla Bug 151884

I consider this a bug, and you probably don't. 

I sometimes need to use ant with jvms that are not distributed by gentoo, and
this worked for years. Now in ant-core-1.6.5-r14 /usr/bin/ant expressly runs
java-config to force the value of JAVA_HOME. I hate that behavior. I want
/usr/bin/ant to honor JAVA_HOME however I set it.

Yeah, and we prefer to keep the packages in portage working correctly... :P

We're not using JAVA_HOME anymore because it's tied to your env, you have to
source /etc/profile after changing it, it's not flexible enough - if you set
JAVA_HOME to 1.4 jdk, apps needing 1.5 would break etc. So using java-config in
launchers isn't only the case of ant, but pretty much anything gen-2. The best
thing you can do is to write metadata for your external VM's and put it in
/usr/share/java-config-2/vm - you can base it on some existing one. Then you
can set the VM as your user VM and run stuff with it, or use GENTOO_VM env
variable for temporary changes.

Creating my own metadata profiles in /usr/share/java-config-2/vm hasn't been a
satsifactory experience.  Briefly, I put things that I install myself such as
Sun JVM's in /usr/local.  If I create a metadata profile for such a JVM and
select the JVM as the system JVM, java -version returns the errors:

* Home for VM 'my-sun-j2sdk1.4.2_12' does not exist:
/usr/lib/jvm/my-sun-j2sdk1.4.2_12
* Invalid System VM: my-sun-j2sdk1.4.2_12

What the hell is that?  In the metadata I specified the correct location of the
JVM home, and java-config ignores it and seems to require that all jvm's be
installed in /usr/lib/jvm.  Can you make java-config honor the information
that's in the metadata?  Why specify metadata if they are ignored?

You need a symlink in /usr/lib/jvm to point at the JAVA_HOME of your jdk/jre.

ie ln -s /usr/local/myjdk /usr/lib/jvm/my-sun-j2sdk1.4.2_12

Created an attachment (id=171084) [edit]
optionally respect java_home instead of gentoo_vm in run-java-tool

This introduces RESPECT_JAVA_HOME variable which, when set, makes every
run-java-tool based launcher use JAVA_HOME instead of GENTOO_VM.

Created an attachment (id=171085) [edit]
ant launcher patch

This makes ant just run "java" instead of its own detection, so that (in
conjunction with patched java-config) if RESPECT_JAVA_HOME is set, the
run-java-tool launcher will use JAVA_HOME.
Additionally, tools.jar is taken from JAVA_HOME instead of java-config --tools.

Created an attachment (id=171087) [edit]
eclass patch unsetting RESPECT_JAVA_HOME for java building

To prevent problems with building existing packages due to user's env,
RESPECT_JAVA_HOME is set in the eclass. Packages that on the other hand need it
(icedtea[6]) can set it afterwards.

*** Bug 217572 has been marked as a duplicate of this bug. ***

After discussion with betelgeuse, the change is to ant script only, not general
run-java-tool and the variable is called ANT_RESPECT_JAVA_HOME which, if set
and JAVA_HOME is set, it's not overriden.
Commited in ant-core-1.7.1-r2