Re: Using `{.gcsafe.}` on a global string

[sschwarzer]

Thanks for your answers and the code suggestion. I see what you're doing here, 
but I need the same temporary directory for all threads. :-)

Would the approach with `deepcopy` [as in the 
manual](https://nim-lang.org/docs/manual.html#threads-gc-safety) be safe?
    
    
    import os
    import posix_utils
    import strformat
    import threadpool
    
    
    let tempRootPath = mkdtemp("vppdiff")
    var tempRootPathPerThread {.threadvar.}: string
    
    proc xmiFilePath(fileNumber: int, cleaned: bool): string =
      let cleanedSuffix = "_cleaned"
      {.gcsafe.}:
        deepcopy(tempRootPathPerThread, tempRootPath)
      return tempRootPathPerThread / fmt"xmi{fileNumber}{cleanedSuffix}.xmi"
    
    var fv = spawn xmiFilePath(1, false)
    
    echo ^fv
    
    
    Run

I'm looking forward to the new GC. :-)