Run conditions should be passed Launcher object so that the conditions may be allowed to run scripts within the build, e.g call a Shell or groovy script.

Current implementations are

public abstract boolean runPrebuild(final AbstractBuild<?, ?> build, final BuildListener listener) throws Exception;

public abstract boolean runPerform(final AbstractBuild<?, ?> build, final BuildListener listener) throws Exception;

These should be extended to
(final AbstractBuild<?, ?> build, final BuildListener listener, final Launcher launcher)