I just recompiled SVN and when intended to install visual package, some error shown:
Unable to find file "datetimepicker.pas".
If it belongs to your project, check search path in
Project -> Compiler Options -> Search Paths -> Other Unit Files. If this file belongs to a package, check the appropriate package compiler options. If this file belongs to Lazarus, make sure compiling clean. If the file belongs to FPC then check fpc.cfg. If unsure, check Project -> CompilerOptions -> Test
It is strange, as I do not use datetimepicker, probably not the lib as well. The same error is shown when I wanted to install ATSynedit.