Presence of unrelated large file causes nimble to hang
I haven't been able to investigate the cause of this yet.

Reproducing is simple:

```bash
# make a new empty project
> mkdir newproject

> cd newproject

> nimble init  # leave all options as default

> nimble setup  # this works
     Info:  "nimble.paths" is generated.
     Info:  "config.nims" is set up.

# generate large 10GB file
> dd if=/dev/urandom of=random.dat bs=1M count=10240

> nimble setup  # this no longer works, it hangs
```

This doesn't just apply to `nimble setup`, it's also `nimble deps`, `nimble install`, etc.

Is nimble reading and attempting to parse this file?