Issue

We have a modified menus.pas.

uses ...,Controls,...;

The compiler raised a fatal error:

[DCC Fatal Error] Menus.pas(*): F2051 Unit Controls was compiled with a different version of Menus.TPopupMenu

tried:

deleted all dcu in the project.

build

build all

tried adding the file to library path which leads to add db folder(from vcl too) and then to

[DCC Error] jpeg.pas(872): E2065 Unsatisfied forward or external declaration: 'jpeg_save_markers'

which is a dead end.

deleted the controls.dcu (all 3) and the delphi did not know automaticaly to recompile them, instead reported that controls.dcu is missing.

Solution

Here is how I handle modifications to VCL source files:

Make a copy of the file in your project structure. Either add the file to your project, or make sure the search path finds your modified file.
Make modifications, but only in the implementation section. You are not able to modify the interface section if you use any other units that themselves use the unit you are modifying.
Explicitly set the compiler options at the top of the modified source file. Use default Delphi options, as found by pressing CTRL+O O in a default vanilla project.

I'd guess that one of the final two bullet points is what is tripping you up.

Answered By - David Heffernan

Answer Checked By - Mildred Charles (PHPFixing Admin)