HOWTO: Find the feature that contains a plugin

Tycho is awesome.

However, like all build systems, it has its limitations.

One such limitation is that when you're building against a target platform, and something's missing, you get errors such as these:

[INFO] Cannot complete the request.  Generating details.
{org.osgi.framework.executionenvironment=OSGi/Minimum-1.0,OSGi/Minimum-1.1, osgi.ws=cocoa, osgi.arch=x86, osgi.os=macosx, org.eclipse.update.install.features=true, org.osgi.framework.system.packages=}
[Software being installed: org.jboss.tools.tptp.feature.feature.group 1.2.0.qualifier, Missing requirement: org.eclipse.tptp.platform.instrumentation.ui 4.4.1.v201009092123 requires 'bundle org.eclipse.hyades.probekit [4.2.0,5.0.0)' but it could not be found, Cannot satisfy dependency: org.eclipse.tptp.platform.instrumentation.ui.feature.group 4.3.1.v201009092123-797908s73533D4H6D56 depends on: org.eclipse.tptp.platform.instrumentation.ui [4.4.1.v201009092123], Cannot satisfy dependency: org.jboss.tools.tptp.feature.feature.group 1.2.0.qualifier depends on: org.eclipse.tptp.platform.instrumentation.ui.feature.group 4.3.0]
[ERROR] Internal error: java.lang.RuntimeException: org.eclipse.equinox.p2.core.ProvisionException: No solution found because the problem is unsatisfiable. -> [Help 1]
org.apache.maven.InternalErrorException: Internal error: java.lang.RuntimeException: org.eclipse.equinox.p2.core.ProvisionException: No solution found because the problem is unsatisfiable.

The important part of that error message is as follows:

org.jboss.tools.tptp.feature.feature.group 1.2.0.qualifier
   requirement: org.eclipse.tptp.platform.instrumentation.ui 4.4.1.v201009092123 
      requires 'bundle org.eclipse.hyades.probekit [4.2.0,5.0.0)' 
         but it could not be found

org.eclipse.tptp.platform.instrumentation.ui.feature.group 4.3.1.v201009092123-797908s73533D4H6D56 
   depends on: org.eclipse.tptp.platform.instrumentation.ui [4.4.1.v201009092123]
     dependency: org.jboss.tools.tptp.feature.feature.group 1.2.0.qualifier 
        depends on: org.eclipse.tptp.platform.instrumentation.ui.feature.group 4.3.0]

So, how do you find which feature contains that plugin, so that you can add it to your target platform?

First, you need access to the repository. If you have direct server access to the repository from which the plugin comes (eg., the TPTP Helios update site), you can run this script in the root of that repository.

If you don't have server access (eg., you can't ssh to dev.eclipse.org and look in ~/downloads/tptp/updates/helios), then you can pull down a zip of the site (or use a p2.mirror script to fetch a copy of the site to your local machine)... and then run this script in the root of that repository.

Essentially the script finds matching feature jar files, unpacks them to extract the feature.xml files therein, and then greps those files for lines which suggest an included plugin matching the pattern for which you're searching:

$ findInFeature platform.probekit
./features/org.eclipse.tptp.platform.probekit_4.5.1.v201009092123-7H7BF8PAkF7B77ZARCNEK.jar
   <plugin
         id="org.eclipse.tptp.platform.probekit"

./features/org.eclipse.tptp.platform.trace_4.5.1.v201009092123-7L7O8bBgJ9E99jAfGWEM.jar
   <plugin
         id="org.eclipse.tptp.platform.probekit.launch"

From there, it's a trivial exercise to add another line item into your target platform file. First, paste in the feature jar:

./features/org.eclipse.tptp.platform.probekit_4.5.1.v201009092123-7H7BF8PAkF7B77ZARCNEK.jar

Then use vim to pattern-replace that string:

:%s/.\+\/\(org.\+\)_\(\d\+.\+\)\.jar/\t\t\t/g

And you'll end up with a new .feature.group added to the target:

<unit version="4.5.1.v201009092123-7H7BF8PAkF7B77ZARCNEK" id="org.eclipse.tptp.platform.probekit.feature.group"/>