can't run on UNC path

[puruneko]

#### problem

I tried to run Nim on UNC path (ex: `\\sampleserver\path\to\nimfile\sample.nim` 
), but failed to compile.

Please let me know if you know how to solve this problem.

#### execute command
    
    
    nim c -r "\\sampleserver\path\to\nimfile\sample.nim"
    
    
    Run

#### error message
    
    
    oserr.nim(94)            raiseOSError
    Error: unhandled exception:
    Additional info: "\\\\sampleserver" [OSError]
    
    
    Run

#### source
    
    
    #The problem is that it fails to compile, so please don't go too deep into 
the contents of this source code.
    import os
    var fp: File
    let openOk = fp.open(r"\\sampleserver\path\to\csv\sample.csv", fmRead)
    if openOk:
        echo fp.readAll()
    else:
        raise newException(ValueError, "error.")
    
    
    Run

Please correct any typos on your own brain.