Class referenced by skinEmbed in CSS does not seem to be compiled when using include-stylesheet

Document describes 'include-stylesheet' compiler option to be: This option compiles classes that are referenced by the stylesheet before including the stylesheet in the SWC file.

This seems to work when compiling a CSS file with class reference to a programmatic skin.
When I did an embed of a skinClass using the syntax: Embed(skinClass="customSkin"), and the skin swc is not in the library path, I expected a compiler error, but none was reported.

Steps to reproduce:
1. Get bugfiles and unzip
2. Compile the custom class and defaults.css into a library swc in the command line:
SkinningEmbed > compc -o bin\SkinningEmbed.swc -source-path src -include-classes com.custom.CustomButton -include-stylesheet defaults.css src\defaults.css

Actual Results:
No compiler error

Expected Results:
Expected a compiler error for classes 'Button_upSkin1' and 'Button_upSkin2' not found since the swc that contains the skin classes is not in the library path.

Workaround (if any):