[TODO] `nim --version` doesn't show git hash (when installed via `choosenim '#head'`)
```
./bin/choosenim --nimbleDir:$HOME/.nimble_choosenim '#head'
   Switched to Nim #head

 ~/.nimble_choosenim/bin/nim --version
Nim Compiler Version 0.18.1 [MacOSX: amd64]
Copyright (c) 2006-2018 by Andreas Rumpf

active boot switches: -d:release
```


but

```
brew install --HEAD nim
nim --version
Nim Compiler Version 0.18.1 [MacOSX: amd64]
Copyright (c) 2006-2018 by Andreas Rumpf

git hash: 992300b30057e2b3b489b90fb0e7011607e3e8cf
active boot switches: -d:release -d:useLinenoise
```

=> ` ~/.nimble_choosenim/bin/nim --version` should show git hash, as is the case for nim installed by brew