[PATCH FOR REVIEW]: Unset JAVA_HOME and JDK_HOME prior to building OpenJDK

[Andrew John Hughes]

2009/8/25 Mark Wielaard <mark at klomp.org>:
> On Tue, 2009-08-25 at 09:29 -0400, Lillian Angel wrote:
>> Andrew John Hughes wrote:
>> > This simple patch for IcedTea6 unsets JAVA_HOME and JDK_HOME before
>> > starting an OpenJDK build.  If JAVA_HOME is set, an OpenJDK build will
>> > fail.
>> >
>> > Ok to commit?
>> >
>> > ChangeLog:
>> >
>> > 2009-08-25  Andrew John Hughes  <ahughes at redhat.com>
>> >
>> >         * Makefile.am:
>> >         Unset JAVA_HOME and JDK_HOME before building.
>>
>> I am not thrilled with the idea of unsetting env vars on a system. I
>> think maybe it would be better for configure to fail and give an error
>> message if either of these are set.
>
> Why does the build fail if any of these are set in the first place?

Because Sun designed it to do so. Clearly you don't have JAVA_HOME set
by default on your system (some distros do this) or you would have had
the fun of the OpenJDK build failing.
See: http://hg.openjdk.java.net/jdk7/build/raw-file/tip/README-builds.html#linux

> I agree that in general it is better to have configure figure out
> settings. That is really what it is for.
>
> The GNU Make manual actually warns not to rely on environment variables:
>
>        It is not wise for makefiles to depend for their functioning on
>        environment variables set up outside their control, since this
>        would cause different users to get different results from the
>        same makefile. This is against the whole purpose of most
>        makefiles.
>        http://www.gnu.org/software/automake/manual/make/Environment.html
>

Unfortunately, that is how the entire OpenJDK build works.  We already
set 30-40 variables in Makefile.am.

> Cheers,
>
> Mark
>
>



-- 
Andrew :-)

Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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