Remove trailing space in nim r command; Amend one error message

Author: iacore

compiler/extccomp.nim

@@ -763,8 +763,8 @@ template tryExceptOSErrorMessage(conf: ConfigRef; errorPrefix: string = "", body
     if errorPrefix.len > 0:
       rawMessage(conf, errGenerated, errorPrefix & " " & ose.msg & " " & $ose.errorCode)
     else:
-      rawMessage(conf, errGenerated, "execution of an external program failed: '$1'" %
-        (ose.msg & " " & $ose.errorCode))
+      rawMessage(conf, errGenerated, "execution of an external program failed: '$1' error code: $2" %
+        [ose.msg, $ose.errorCode])
     raise
 
 proc getExtraCmds(conf: ConfigRef; output: AbsoluteFile): seq[string] =

compiler/nim.nim

@@ -116,7 +116,8 @@ proc handleCmdLine(cache: IdentCache; conf: ConfigRef) =
       if cmdPrefix.len > 0: cmdPrefix.add " "
         # without the `cmdPrefix.len > 0` check, on windows you'd get a cryptic:
         # `The parameter is incorrect`
-      execExternalProgram(conf, cmdPrefix & output.quoteShell & ' ' & conf.arguments)
+      let cmd = cmdPrefix & output.quoteShell & ' ' & conf.arguments
+      execExternalProgram(conf, cmd.strip(leading=false,trailing=true))
     of cmdDocLike, cmdRst2html, cmdRst2tex: # bugfix(cmdRst2tex was missing)
       if conf.arguments.len > 0:
         # reserved for future use