[Reopened] [Dapper] Eclipse startup script should respect jwm setting via update-alternatives

[Erich Pawlik]

[Dapper] eclipse 3.1.1-8ubuntu2

I have changed by default jvm to sun java 1.5 via the update-alternatives mechanism (using the package provided in the Dapper repositories).

The eclipse startup script is ignoring this setting even after I did change the default jvm inside eclipse. It cycles through the entries in /etc/eclipse/java_home and picks the first one that happens to be gij.

Of cause there are several ways to work around this such as using the -vm option. But I feel that eclipse should be good Debian citizen.

The bug has been rejected with the argument that update-alternatives is not able to handle JAVA_HOME. This argument is not very convincing. Basically the bug could be fixed by adapting the heuristics used in the eclipse startup script to determine $JAVA_HOME.

Because I am not very familiar with shell scripting and don't know anything about the Debian packing system, I don't attempt a fix. However the basic strategy to fix the issue could be to determine the jvm from update-alternatives and put the line for the right jvm at the beginning of /etc/eclipse/java_home before handing over /etc/eclipse/java_home to the command to determine javahomelist.

To prove the feasibility of my approach: The following (I admit a bit clumpsy) script writes the required variant of /etc/eclipse/java_home to standard output.

#!/bin/bash
javainterpreter=`update-alternatives --display java|grep 'link currently points to'|awk '{print $5}'`
myjavahome=`cat /etc/eclipse/java_home|awk -v interpret="$javainterpreter" 'interpret ~ $0 {print}'`
cat /etc/eclipse/java_home|awk -v myhome="$myjavahome" 'BEGIN {print myhome} myhome !~ $0 {print}'|grep -v '^$'|grep -v '^#'

Regards

Erich Pawlik

[Joachim Beckers (jbeckers)]

With the new sun-java5 packages, eclipse won't run.

A popup box says:
"The custom vm you have chosen is not a valid executable."

On the command line:
joachim@madkeunnen:~$ eclipse
using specified vm: /usr/lib/j2sdk1.5-sun

This is the same problem as above, that is: eclipse doesn't follow the settings provided by /etc/alternatives (where I have /usr/lib/jvm/java-1.5.0-sun set), but uses the $JAVA_HOME. If I set that to /usr/lib/jvm/java-1.5.0-sun, everything works fine.

[Erich Pawlik (erichpawlik)]

The situation described by Joachim Beckers has another twist: /etc/eclipse/java_home doesn't contain /usr/lib/jvm/java-1.5.0-sun. If I don't set $JAVA_HOME and the new sun-java5 package is the only Java package that is installed on the system, Eclipse no longer will work.

Btw: My proposed fix assumes that /etc/eclipse/java_home contains the correct path to the jvm and therefore doesn't work any more.

[Erich Pawlik (erichpawlik)]

See also bug #45347

[Dennis Kaarsemaker (dennis)]

Jochim, Erich - that is a very different bug which is already filed
serveral times. Please look at the manpage for update-java-alternatives

[Dennis Kaarsemaker (dennis)]

Ehrm, I forgot that eclipse is being weird about this - sorry

[R. A. Rivas Diaz (rivasdiaz)]

I have described a way to solve this problem, but on a bug reported against java-common, the bug #45348.

If java-common is updated with my proposed solution (and the jdks and jres), then eclipse only have to use the same scheme, and with my patch to bug #45347 the problem is solved, although a simpler patch could also work.

[ashok (asoka250)]

This bug is already present in windows too, eclipse 3.0 version goes along with java 1.4.x and below versions, i think its the problem with the eclipse package,

[auspex (auspex)]

I agree with Erich (& Dennis - I'm not sure why you retracted your comment!)

update-alternatives (and update-alternatives-java) are the _proper_ way to set your default VM. eclipse should be respecting that.

I agree that "update-alternatives is not able to handle JAVA_HOME" is an unconvincing argument. Eclipse sets JAVA_HOME for itself, and should use the alternatives system to find where that should be.

[David Császár (p5)]

i'm also stuck on this.
- installed java-5
- installed eclipse
-> eclipse ran fine
- installed java-6
- uninstalled java-5
-> eclipse from the menu gives: The custom VM you have chosen is not a valid executable.
- uninstalled completely/reinstalled eclipse
-> same problem

eclipse from the command line is fine w/ and w/o JAVA_HOME

[George Pollard (porges)]

The sanest fix should be to have "/etc/eclipse/java_home" have "/usr/lib/jvm/default-java" as the first line.

[auspex (auspex)]

On October 28, 2008 04:09:59 George Pollard wrote:
> The sanest fix should be to have "/etc/eclipse/java_home" have
> "/usr/lib/jvm/default-java" as the first line.

Not very useful if you don't have such a file! The point of using
update-alternatives is that this is the way that java (and other) packages
are supposed to set the default for use by any applications - so Eclipse
should respect that, instead of using its own settings. If I use
update-alternatives or the more specific update-java-alternatives to set a
VM, then "/usr/bin/javac" and "/usr/bin/java" point to the java I've chosen,
via /etc/alternatives - eclipse should be able to do the same.
--
derek

[Wolf von Bleichert (wolf-von-bleichert-koeln)]

Well, I had the same error (the vm ....) after upgrading ubuntu 8 to 9.
I'd installed java-6-sun-1.6.0.13 but after the update my $JAVA_HOME pointed to java-6-sun-1.6.0.10.
Crap! Short discussion with my environment settings does not solve the problem. :-(
Checking out "/usr/bin/java" I saw that "someone" changed the link too.
Yeap!
Instead of linking "/usr/bin/java" to "/usr/lib/jvm/java-6-sun-1.6.0.13/jre/bin/java" there was this @³½¬! version 1.6.0.10 again.
Fixing the link solved all problems. Sun rises:-).

Does some nerd wrote an ubuntu update routine that kills my environment this way?
Go and get him!
Nail his fingers to the keyboard!
:-) No, just kidding! Errors making you human buddy! :-)
Maybe I overlooked something too!

[Philippe Coval (rzr)]

hi,
here is an offtopic question :

About your script, is there a policy to setup jvm per applications ?
For tuxguitar package I had to write a script that guess best installed jvm, but i am not very proud of it ...

Regards

[Niels Thykier (niels-thykier)]

We will try to fix this in eclipse 3.5.0-1

~Niels

[Niels Thykier (niels-thykier)]

There are no longer any special hacks from our side that chooses the JVM.

~Niels