DMD Stdio Linker Oddities

[Jake Pittis via Digitalmars-d-learn]

I'm posting this in Learn because I'm assuming I've done 
something wrong rather than discovered a bug.

Running `dmd -main main.d` with the following 3 files produces 
the following linker error.

```
$ dmd -main main.d
Undefined symbols for architecture x86_64:
  "_D13linking_fails12__ModuleInfoZ", referenced from:
      _D4main12__ModuleInfoZ in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to 
see invocation)
Error: linker exited with status 1
```

```
// main.d
import linking_succeeds;
import linking_fails;
```

```
// linking_succeeds.d
import std.range;
```

```
// linking_fails.d
import std.stdio;
```

In the `linking_fails.d` file, if I replace the stdio import with 
`import std.algorithm`, running `dmd -main main.d` succeeds. 
Somehow stdio is causing the linker to fail.

Any idea what's going on or how to fix it? Thanks!

(DMD64 D Compiler v2.072.0, macOS Sierra 10.12)