Do not actually download JARs if only dependency information is queried

[sschuberth]

It looks to me as if sbt dependencyTree is actually downloading the JARs, see e.g. lines like

[info] downloading https://repo1.maven.org/maven2/commons-logging/commons-logging/1.2/commons-logging-1.2.jar ...

whereas just querying the dependencies would only require to download the POMs, not the JARs. I believe by default only the absolutely necessary files should be downloaded, and only as an option, if at all, also downloads the JARs.

The use case is that we are only interested in the dependencies and their respective licenses, but not in building the code. As such we don't need the JARs.

[jrudolph]

Yeah, good point, not sure how easy it is to prevent ivy from doing that, though.

[jrudolph]

I had a try at this in https://github.com/jrudolph/sbt-dependency-graph/tree/jr/fix-130-by-only-downloading-poms-for-update but it doesn't seem to work so far.