Unspecified build dependency on "ruby"

```
[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.5.0:exec (map-tokens) on project rust-netbeans: Command execution failed.: Cannot run program "ruby" (in directory "C:\Users\hlavac\rust-netbeans\rust-netbeans"): CreateProcess error=2, Systém nemůže nalézt uvedený soubor -> [Help 1]
```

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