Hi,
It’s likely being triggered by enabling that option, which likely does a -Wundef (using undefined symbols in macros becomes a warning). That, combined with a -Werror, is promoted to a compilation error.
If you still do need VTK_EXTRA_COMPILER_WARNINGS you can try disabling warnings for system headers (I assume the offending loss_Sort.h belongs to a system library), by adding a compiler flag:
- For GCC-like compilers:
-isystem <path of a dependency include path>. - For MSVC:
/external:I <path of a dependency include path>.
Those flags disable warnings coming from headers of libraries you’re using in your project. Hopefully you will get rid of that external header warning/error.
take care,
Paulo