Exclude `core.jar` from sketchbook copies.

[zedseven]

Starting with Processing 4, the IDE will refuse to load a sketchbook library if it contains the core.jar.

Zipped versions are unaffected since they didn't contain the file anyways, but it makes it a pain to develop with.

Here is the error that is shown:

The library "${project.name}" cannot be used
because it contains the processing.core libraries.
Please contact the library author for an update.

[SableRaf]

Thanks for your contribution Zacchary 🙂

@prisonerjohn could you review this and merge it?

[vincentsijben]

So, I ran into this myself this afternoon. While this PR is not yet merged, in the meantime you could simply change the following in resources/build.xml (thanks for https://github.com/ndsh/occasional-knowledge)

<target name="copyToSketchbook">
	…
	<fileset dir="${project.tmp}/${project.name}"/>
</target>

into

<target name="copyToSketchbook">
	…
<fileset dir="${project.tmp}/${project.name}">
		<!--
			https://github.com/processing/processing-library-template/pull/31
			To avoid the following error in Processing 4.0 and newer:
			The library "${project.name}" cannot be used
			because it contains the processing.core libraries.
			Please contact the library author for an update.
		 -->
		<exclude name="**/core.jar"/>
	</fileset>
</target>

[benfry]

Thanks for the fix @zedseven.