Do not put IFDEF with relative paths in your .dpr as the Delphi IDE cannot match them in the .dproj
Posted by jpluimers on 2018/12/20
The Delphi IDE manages the .dpr and .dproj files for, trying to keep them in sync.
Some information is duplicated between the two, especially files referenced by relative paths: those files are contained in your project.
This means you cannot do something like this in your .dpr file:
{$IFDEF DEBUG}
Debug in '..\..\..\..\Shared\Debug.pas';
{$ELSE}
Debug in '..\Debug.pas'
{$ENDIF}
There is no equivalent for this in the .dproj and it will confuse the IDE which file now actually is or is not inside your project.
Better to leave the file outside of your project, then modify the RELEASE/DEBUG search paths to have the correct one.
Even better is to have just one Debug.pas file containing the changes.
–jeroen
The Wiert Corner - irregular stream of stuff 
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