The glslang standalone command line tool does not support system includes (#include <foo>)

[gaberundlett-tuxedo]

This should just be supported. The standalone tool's includer also just returns null, so in order for a user to even understand that the command line tool is incomplete, they'd need to look into the source. See line 127 of the StandAlone/DirStackFileIncluder.h

glslang/StandAlone/DirStackFileIncluder.h

Lines 127 to 131 in b3a6aa7

	// Not implemented yet; returning nullptr signals failure to find.
	virtual IncludeResult* readSystemPath(const char* /*headerName*/) const
	{
	return nullptr;
	}