On a second though, the actual error seems to be elsewhere, so still can use proper indexing
set(CMAKE_Pascal_COMPILER "@CMAKE_Pascal_COMPILER@")
set(CMAKE_Pascal_COMPILER_ARG1 "@CMAKE_Pascal_COMPILER_ARG1@")
set(CMAKE_Pascal_COMPILER_LOADED 1)
set(CMAKE_Pascal_COMPILER_VERSION "@CMAKE_Pascal_COMPILER_VERSION@")
set(CMAKE_Pascal_COMPILER_ENV_VAR "FPC")
set(CMAKE_Pascal_SOURCE_FILE_EXTENSIONS "pas" "pp")
set(CMAKE_Pascal_IGNORE_EXTENSIONS ppu;PPU;h;H;o;O;obj;OBJ;def;DEF;rc;RC)
set(CMAKE_Pascal_LINKER_PREFERENCE Prefered)
set(CMAKE_Pascal_OUTPUT_EXTENSION_REPLACE 1)
set(CMAKE_Pascal_OUTPUT_EXTENSION ".o")