[Lazarus] Units in package not found

[Hans-Peter Diettrich]

I've created a package for the FPDoc units, for use in the FPDocManager 
(see examples/fpdocmanager). While the IDE (code tools) can find all the 
units in the package, I get an compiler error about units not found. 
When I made the package "manual compile", most errors disappeared, but 
when I patched the units, now again the unit "dwlinear" is not found:

PPU Loading D:\repos\fpc-2.5.trunk\utils\fpdoc\lib\i386-win32\dwlinear.ppu
PPU Source: dwlinear.pp not found
Recompiling dwlinear, checksum changed for dWriter
dwlinear.pp(11,21) Fatal: Can't find unit dwlinear used by FPDocManager

A very strange thing is the last error message, from within the unit 
that cannot be found.

What's wrong?

DoDi