This took me some time to find and work out so I am posting this in case I ever need again. I was getting mapping errors so wanted to see what Fluent NH spits out.

public class FluentNHUtil
{
	string schemaExportPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, 
		"FluentNHMappings");
	[Observation]
	public void compile_mappings_to_disk()
	{
		if (Directory.Exists(schemaExportPath))
			Directory.Delete(schemaExportPath, true);
		Directory.CreateDirectory(schemaExportPath);
		var model = new ReportingModelPersistenceMappingHandler().CreateModel();
		model.CompileMappings();
		model.WriteMappingsTo(schemaExportPath);		
	}
	
}
public class ReportingModelPersistenceMappingHandler
{
	public MappingConfiguration Handle(MappingConfiguration mappingConfiguration)
	{
		mappingConfiguration.AutoMappings.Add(CreateModel());
		mappingConfiguration.HbmMappings.AddFromAssembly(GetType().Assembly);
		return mappingConfiguration;
	}

	public AutoPersistenceModel CreateModel()
	{
		//the Components convention seems redundant but is dealing with an oddity in FluentNH
		return AutoMap.Assembly(GetType().Assembly)
			.Setup(s =>
					{
						s.IsComponentType = type => type.Namespace.Contains("Components");
					})
			.Conventions.Add(
			new ReportingModelIdConvention(),
			DefaultLazy.Never(),
			new PluralizeTableNameConvention(),
			new HasManyDefaultConvention(),
			new LabNumberComponentConvention()
			).Where(t => t.Namespace.Contains(GetNamespaceConvention()) && t.Namespace.Contains("Components")==false);
	}

	private string GetNamespaceConvention()
	{
		return GetType().Namespace + ".Model";
	}
}