stack build in WSL - openAnonymousTempFileFromDir: inappropriate type (Is a directory)

### Steps to reproduce

* have Ubuntu 18.04 WSL
* install Nix in it
* git clone https://github.com/fairy-tale-agi-solutions/fairy-tale-artificial-general-intelligence-solutions.git
* checkout revision 6354fcca2bb37ad4f4c6b05fdcb55b09734f5164
* run `nix-shell` in project root
* run `stack build --verbose`

### Expected

Project to build successfully.

### Actual

```
stack build --verbose
2.1.3.1 x86_64 hpack-0.31.2
2019-08-19 14:39:27.610378: [debug] Checking for project config at: /home/neo/Projects/fairy-tale-artificial-general-intelligence-solutions/Sources/Razvan Flavius Panda/Haskell/artificial-general-intelligence/stack.yaml
2019-08-19 14:39:27.611197: [debug] Loading project config file stack.yaml
2019-08-19 14:39:27.612420: [error] openAnonymousTempFileFromDir: inappropriate type (Is a directory)
```

### Stack version

```
$ stack --version
2.1.3.1 x86_64 hpack-0.31.2
```

### Method of installation

Installed stack via Nix.

Reproduce the failure in Ubuntu 18.04 WSL using the listed Nix setup, revision 6354fcca2bb37ad4f4c6b05fdcb55b09734f5164, and `stack build --verbose`. Start with `stack.yaml` loading and the `openAnonymousTempFileFromDir` error path; done means the project builds successfully in that environment.

Written by the indexing model from the issue text.