I downloaded imaginglib0264.zip and tried to compile it using BuildLibraryFPC.sh.  Tje const declarations in the function TPCXFileFormat.LoadData, namely:
function TPCXFileFormat.LoadData(Handle: TImagingHandle;
  var Images: TDynImageDataArray; OnlyFirstLevel: Boolean): Boolean;
const
  ifMono: TImageFormat = TImageFormat(250);
  ifIndex2: TImageFormat = TImageFormat(251);
  ifIndex4: TImageFormat = TImageFormat(252);

generates the error messages:

ImagingPcx.pas(94,26) Warning: range check error while evaluating constants (250 must be between 0 and 225)
ImagingPcx.pas(94,43) Error: range check error while evaluating constants (250 must be between 0 and 225)
ImagingPcx.pas(95,28) Warning: range check error while evaluating constants (251 must be between 0 and 225)
ImagingPcx.pas(95,45) Error: range check error while evaluating constants (251 must be between 0 and 225)
ImagingPcx.pas(96,28) Warning: range check error while evaluating constants (252 must be between 0 and 225)
ImagingPcx.pas(96,45) Error: range check error while evaluating constants (252 must be between 0 and 225)
ImagingPcx.pas(379) Fatal: There were 3 errors compiling module, stopping
Fatal: Compilation aborted

I am using the Free Pascal Compiler (fpc) for x86_64 version 3.2.0 (released 2021/04/29) on Linux.

Is there anywhere to report bugs other than in this forum?