Use Nim binary if it exists.

src/babel.nim

@@ -404,7 +404,7 @@ proc buildFromDir(pkgInfo: TPackageInfo, paths: seq[string]) =
   for bin in pkgInfo.bin:
     echo("Building ", pkginfo.name, "/", bin, " using ", pkgInfo.backend,
          " backend...")
-    doCmd("nimrod $# -d:release --noBabelPath $# \"$#\"" %
+    doCmd(getNimBin() & " $# -d:release --noBabelPath $# \"$#\"" %
           [pkgInfo.backend, args, realDir / bin.changeFileExt("nim")])
 
 proc saveBabelMeta(pkgDestDir, url: string, filesInstalled: TSet[string]) =

src/babelpkg/tools.nim

@@ -31,11 +31,17 @@ template cd*(dir: string, body: stmt) =
   body
   setCurrentDir(lastDir)
 
+proc getNimBin*: string =
+  result = "nim"
+  if findExe("nim") != "": result = "nim"
+  elif findExe("nimrod") != "": result = "nimrod"
+
 proc getNimrodVersion*: TVersion =
-  let vOutput = execProcess("nimrod -v")
+  let nimBin = getNimBin()
+  let vOutput = doCmdEx(nimBin & " -v").output
   var matches: array[0..MaxSubpatterns, string]
   if vOutput.find(peg"'Version'\s{(\d\.)+\d}", matches) == -1:
-    quit("Couldn't find Nimrod version.", QuitFailure)
+    quit("Couldn't find Nim version.", QuitFailure)
   newVersion(matches[0])
 
 proc samePaths*(p1, p2: string): bool =