From 10bd758d72bdea45db7e5a35d82e4f890b3c231c Mon Sep 17 00:00:00 2001
From: Clyybber <darkmine956@gmail.com>
Date: Thu, 12 Mar 2020 10:34:06 +0100
Subject: [PATCH] Fix #13633

---
 compiler/extccomp.nim | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/compiler/extccomp.nim b/compiler/extccomp.nim
index 34552e6f3bbf1..6f52e777a7e99 100644
--- a/compiler/extccomp.nim
+++ b/compiler/extccomp.nim
@@ -998,7 +998,8 @@ proc writeJsonBuildInstructions*(conf: ConfigRef) =
       f.write escapeJson(x)
 
   proc cfiles(conf: ConfigRef; f: File; buf: var string; clist: CfileList, isExternal: bool) =
-    for i, it in clist:
+    var i = 0
+    for it in clist:
       if CfileFlag.Cached in it.flags: continue
       let compileCmd = getCompileCFileCmd(conf, it)
       if i > 0: lit ",\L"
@@ -1007,6 +1008,7 @@ proc writeJsonBuildInstructions*(conf: ConfigRef) =
       lit ", "
       str compileCmd
       lit "]"
+      inc i
 
   proc linkfiles(conf: ConfigRef; f: File; buf, objfiles: var string; clist: CfileList;
                  llist: seq[string]) =