Choosenim breaks nimble
```
nimble tasks
       Tip: 1 messages have been suppressed, use --verbose to show them.
     Error: Could not read package info file in /home/papillon/esperimenti/nimgraph/nimgraph.nimble;
        ...   Reading as ini file failed with: 
        ...     Invalid section: .
        ...   Evaluating as NimScript file failed with: 
        ...     Error: cannot open '/home/papillon/.nimble/lib/system.nim'.
```