[incquery-dev] Headless building issues

[Ujhelyi Zoltán <ujhelyiz@xxxxxxxxxxxxxxxx>]

Hi,

today I had an issue on my computer with building IncQuery with Maven, where using the incquery-maven-compiler I got strange exceptions about signing of the Guice plug-in.

After a long debugging session, I found out the main issue was that the maven plug-in referenced dependencies two ways: directly as a Maven dependency and transitively as p2 dependency, and more than likely in my computer a combination was selected that were incompatible.

I managed to ask Maven not to use the transitive dependencies (https://git.eclipse.org/c/incquery/org.eclipse.incquery.git/commit/?id=0c07a0b45ab0e4f41380298d1c9544c5603a918e), that solved the issue, but had a side-effect: IncQuery cannot be built with Maven 3.0.5 (used on Hudson by default).

I tried with different versions:
 * 3.1 works, but throws a warning (that can be safely ignored, see http://stackoverflow.com/questions/547805/exclude-all-transitive-dependencies-of-a-single-dependency/7556707#7556707 and https://issues.apache.org/jira/browse/MNG-3832)
 * 3.3 does not throw this exception, but should not be used for the main incquery build, as it requires Java 7 to run - mainly, because Xtend sometimes uses the running JVM version instead of the Java compiler setting to determine what versions to use...
 * I did not test 3.2, but it should work, and the warning should also be fixed...

As Maven 3.1 is from 2013 (https://maven.apache.org/docs/history.html), I don’t think the minimum Maven requirement is a serious issue, but I wanted to give a heads up what to expect. If someone has some problems with this, lets discuss them.

Cheers,
Zoli
-- Zoltán Ujhelyi

Technology Expert
IncQueryLabs Ltd.