Strange behaviour of rdmd vs. dmd concerning main function

[via Digitalmars-d-learn]

On Thu, Feb 09, 2017 at 03:39:18PM +0000, berni via Digitalmars-d-learn wrote:
> Now I try to run it with rdmd and dmd and get quite different results:

dmd only compiles in the files you actually pass to it. rdmd
will try to find the required files automatically.

Since you didn't pass the file with the function to dmd, it knows
it exists, but leaves it out of the final link (it assumes it might
come from a library or something). That's why you see the error.

rdmd exists because it handles it more automatically.