Eliminate warnings on Windows. (#382)

chronos/asyncfutures2.nim

@@ -10,7 +10,7 @@
 
 import std/sequtils
 import stew/base10
-import "."/[config, srcloc]
+import "."/srcloc
 export srcloc
 
 when defined(nimHasStacktracesModule):

tests/testbugs.nim

@@ -117,14 +117,14 @@ suite "Asynchronous issues test suite":
     let inpTransp = await afut
     let bytesSent = await outTransp.write(msg)
     check bytesSent == messageSize
-    var rfut = inpTransp.readExactly(addr buffer[0], messageSize)
+    var rfut {.used.} = inpTransp.readExactly(addr buffer[0], messageSize)
 
     proc waiterProc(udata: pointer) {.raises: [Defect], gcsafe.} =
       try:
         waitFor(sleepAsync(0.milliseconds))
-      except CatchableError as exc:
+      except CatchableError:
         raiseAssert "Unexpected exception happened"
-    let timer = setTimer(Moment.fromNow(0.seconds), waiterProc, nil)
+    let timer {.used.} = setTimer(Moment.fromNow(0.seconds), waiterProc, nil)
     await sleepAsync(100.milliseconds)
 
     await inpTransp.closeWait()

tests/testhttpclient.nim

@@ -5,7 +5,7 @@
 #              Licensed under either of
 #  Apache License, version 2.0, (LICENSE-APACHEv2)
 #              MIT license (LICENSE-MIT)
-import std/[strutils, strutils, sha1]
+import std/[strutils, sha1]
 import unittest2
 import ../chronos, ../chronos/apps/http/[httpserver, shttpserver, httpclient]
 import stew/base10

tests/testhttpserver.nim

@@ -5,7 +5,7 @@
 #              Licensed under either of
 #  Apache License, version 2.0, (LICENSE-APACHEv2)
 #              MIT license (LICENSE-MIT)
-import std/[strutils, algorithm, strutils]
+import std/[strutils, algorithm]
 import unittest2
 import ../chronos, ../chronos/apps/http/httpserver,
        ../chronos/apps/http/httpcommon

tests/testshttpserver.nim

@@ -5,7 +5,7 @@
 #              Licensed under either of
 #  Apache License, version 2.0, (LICENSE-APACHEv2)
 #              MIT license (LICENSE-MIT)
-import std/[strutils, strutils]
+import std/strutils
 import unittest2
 import ../chronos, ../chronos/apps/http/shttpserver
 import stew/base10

tests/teststream.nim

@@ -1286,10 +1286,11 @@ suite "Stream Transport test suite":
     var transp3 = await connect(dst2, localAddress = dst3, flags={SocketFlags.ReusePort})
 
     expect(TransportOsError):
-      var transp2 = await connect(dst3, localAddress = ta)
+      var transp2 {.used.} = await connect(dst3, localAddress = ta)
 
     expect(TransportOsError):
-      var transp3 = await connect(dst3, localAddress = initTAddress(":::35000"))
+      var transp3 {.used.} =
+        await connect(dst3, localAddress = initTAddress(":::35000"))
 
     await transp1.closeWait()
     await transp2.closeWait()