Fix issue #10358 (#10383)

* Fix bug: vccexe finds oldest VCC

* echo path to vcvarsall.bat as hint when failed to execute cl.exe

tools/vccexe/vccenv.nim

@@ -39,7 +39,7 @@ proc vccEnvVcVarsAllPath*(version: VccEnvVersion = vsUndefined): string =
     for tryVersion in [vs140, vs120, vs110, vs100, vs90]:
       let tryPath = vccEnvVcVarsAllPath(tryVersion)
       if tryPath.len > 0:
-        result = tryPath
+        return tryPath
   else: # Specific version requested
     let key = $version
     let val = getEnv key

tools/vccexe/vccexe.nim

@@ -46,6 +46,8 @@ const
   sdktypeSepIdx = sdktypePrefix.len
   sdkversionSepIdx = sdkversionPrefix.len
   
+  vcvarsallDefaultPath = "vcvarsall.bat"
+
   helpText = """
 +-----------------------------------------------------------------+
 |         Microsoft C/C++ compiler wrapper for Nim                |
@@ -158,6 +160,10 @@ when isMainModule:
     vccversionValue = vccUndefined
     vcvarsallArg = discoverVccVcVarsAllPath()
 
+  if vcvarsallArg == "":
+    # Assume that default executable is in current directory or in PATH
+    vcvarsallArg = findExe(vcvarsallDefaultPath)
+
   if printPathArg:
     var head = $vccversionValue
     if head.len < 1:
@@ -180,9 +186,16 @@ when isMainModule:
 
   if not noCommandArg:
     # Run VCC command with the VCC process environment
-    let vccProcess = startProcess(
-        commandArg,
-        args = clArgs,
-        options = vccOptions
-      )
-    quit vccProcess.waitForExit()
+    try:
+      let vccProcess = startProcess(
+          commandArg,
+          args = clArgs,
+          options = vccOptions
+        )
+      quit vccProcess.waitForExit()
+    except:
+      if vcvarsallArg.len != 0:
+        echo "Hint: using " & vcvarsallArg
+      else:
+        echo "Hint: vcvarsall.bat was not found"
+      raise

tools/vccexe/vcvarsall.nim

@@ -10,7 +10,6 @@ import strtabs, strutils, os, osproc
 const
   comSpecEnvKey = "ComSpec" ## Environment Variable that specifies the command-line application path in Windows
                             ## Usually set to cmd.exe
-  vcvarsallDefaultPath = "vcvarsall.bat"
 
 type
   VccArch* = enum ## The VCC compile target architectures
@@ -48,11 +47,10 @@ proc vccVarsAll*(path: string, arch: VccArch = vccarchUnspecified, platform_type
   ## verbose
   ##   Echo the command-line passed on to the system to load the VCC environment. Defaults to `false`.
 
-  var vccvarsallpath = path
-  # Assume that default executable is in current directory or in PATH
   if path == "":
-    vccvarsallpath = vcvarsallDefaultPath
+    return nil
   
+  let vccvarsallpath = path
   var args: seq[string] = @[]
   
   let archStr: string = $arch