The build script has a task 'plugins' that will build all plugins. Default behavior is to skip over a plugin when it fails to build. Although there's a build warning, this warning gets lost in the verbose output of the entire build process.
To work around this issue, an optional property is evaluated. When the property "halt.on.plugin.error" is defined, the build will fail when the first plugin failure occurs. However, by default, this property is not defined (nor documented). This leads to quite a few situations where developers are unaware that one or more plugins failed.
The failure condition should be inversed: a build should fail by default when one or more plugins fail, unless a property has been defined to explicitly ignore this (and restore the old behavior).