better error message for implicitly available modules

2 files changed, 6 insertions, 0 deletions

diff --git a/lib/system/channels.nim b/lib/system/channels.nim
index d0294322a..9c3cc93e0 100644
--- a/lib/system/channels.nim
+++ b/lib/system/channels.nim
@@ -13,6 +13,9 @@
 ##

 ## **Note:** The current implementation of message passing is slow and does

 ## not work with cyclic data structures.

+  
+when not defined(NimString): 
+  {.error: "You must not import this module explicitly".}
 

 type

   pbytes = ptr array[0.. 0xffff, byte]

diff --git a/lib/system/threads.nim b/lib/system/threads.nim
index 7d74de92d..104ca63c1 100644
--- a/lib/system/threads.nim
+++ b/lib/system/threads.nim
@@ -39,6 +39,9 @@
 ##    createThread(thr[i], threadFunc, (i*10, i*10+5))
 ##  joinThreads(thr)
   
+when not defined(NimString): 
+  {.error: "You must not import this module explicitly".}
+
 const
   maxRegisters = 256 # don't think there is an arch with more registers
   useStackMaskHack = false ## use the stack mask hack for better performance