If an opDispatch function has a semantic error inside the body a misleading error will be reported at the call site. Example:

--------------------test.d----------------------
struct Foo
{
	int opDispatch(string prop)() @property
	{
		pragma(msg, prop);
		thisFunctionDoesntExist();
		return 1;
	}
} 

void main()
{
 	import std.stdio;
	Foo bar;
	writeln(bar.baz);
}
-------------------------------------------------

Run:
dmd test.d && ./test
baz
test.d(15): Error: undefined identifier 'baz'

The pragma clearly shows that opDispatch template is being instantiated, but it seems to bail when an error is encountered, leading to the "undefined identifier" error.