Procs

proc compile(nimSrcPath: string; outdir = ""; nim = ""; additionalFlags = "") {.
    ...raises: [OSError, IOError, ValueError, KeyError], tags: [ReadEnvEffect,
    ReadDirEffect, ReadIOEffect, ExecIOEffect, RootEffect, WriteIOEffect,
    WriteDirEffect], forbids: [].}

outdir empty means same dir as nimSrcPath Source   Edit