Compile issue

I’m trying to compile a project using compc from command line.

Using


compc -output ./mybin/aaa.swc -include-classes custom.Test   -compiler.source-path ./src ./messages -include-resource-bundles strings  -compiler.library-path ./flex_lib 

gives me the following error:
The definition of base class BitmapAsset was not found.

Although,


compc -output ./mybin/aaa.swc -include-classes custom.Test   -compiler.source-path ./src ./messages -include-resource-bundles strings  

compiles fine.

Any ideas why adding to the library path a folder with the swc I want to use generates an error?

Thanks.