HowTo define a HarvestDirectory element in a library (WixLib) so the Wix projects associated with the library does not need to implement it?

Question

We've defined a conditional setup with few main projects and a central library. No when we try to harvest a directory in a library (WixLib) the ComponentGroupName "reference" goes unresolved.

On the WixLib:

```<HarvestDirectory Include="($sys.CurDir)sistema\saludos">
  <DirectoryRefId>SaludosDir</DirectoryRefId>
  <ComponentGroupName>SaludosCompGroup</ComponentGroupName>
  <PreprocessorVariable>var.preVar</PreprocessorVariable>
</HarvestDirectory>```

Any reference to Component goes unresolved:

      <ComponentGroupRef Id="fooLibraryItems"/>
         <ComponentGroup Id="fooLibraryItems" Directory="INSTALLDIR" >
         <ComponentGroupRef Id ="SaludosCompGroup" />
         <ComponentGroupRef Id ="DespedidasCompGroup"/>
      </ComponentGroup>

Any suggestions?