vcpkg: Fix usage with Visual C++ 2022

Visual Studio 2022 comes with their own vcpkg and sets the VCPKG_ROOT as
part of the 'vcvars.bat' environment.

This change makes sure that the 'vcpkg' program specified by the vcpkg
plugin is being used.

Change-Id: I582a54ed615a2ad8f47814736d4e6dddad9f50cd
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp

@@ -2086,6 +2086,13 @@ CMakeBuildSystem *CMakeBuildConfiguration::cmakeBuildSystem() const
 
 void CMakeBuildConfiguration::addToEnvironment(Utils::Environment &env) const
 {
+    // Use the user provided VCPKG_ROOT if existing
+    // Visual C++ 2022 (and newer) come with their own VCPKG_ROOT
+    // that is incompatible with Qt Creator
+    const QString vcpkgRoot = qtcEnvironmentVariable(Constants::VCPKG_ROOT);
+    if (!vcpkgRoot.isEmpty())
+        env.set(Constants::VCPKG_ROOT, vcpkgRoot);
+
     const CMakeTool *tool = CMakeKitAspect::cmakeTool(kit());
     // The hack further down is only relevant for desktop
     if (tool && tool->cmakeExecutable().needsDevice())

src/plugins/cmakeprojectmanager/cmakeprojectconstants.h

@@ -27,6 +27,7 @@ const char CMAKEFORMATTER_MENU_ID[] = "CMakeFormatter.Menu";
 const char CMAKE_DEBUGGING_GROUP[] = "Debugger.Group.CMake";
 
 const char PACKAGE_MANAGER_DIR[] = ".qtc/package-manager";
+const char VCPKG_ROOT[] = "VCPKG_ROOT";
 
 const char CMAKE_LISTS_TXT[] = "CMakeLists.txt";
 const char CMAKE_CACHE_TXT[] = "CMakeCache.txt";

src/share/3rdparty/package-manager/auto-setup.cmake

@@ -199,7 +199,10 @@ macro(qtc_auto_setup_vcpkg)
   if (EXISTS "${CMAKE_SOURCE_DIR}/vcpkg.json" AND NOT QT_CREATOR_SKIP_VCPKG_SETUP)
     option(QT_CREATOR_SKIP_VCPKG_SETUP "Skip Qt Creator's vcpkg package manager auto-setup" OFF)
 
-    find_program(vcpkg_program vcpkg $ENV{VCPKG_ROOT} ${CMAKE_SOURCE_DIR}/vcpkg)
+    find_program(vcpkg_program vcpkg
+      PATHS $ENV{VCPKG_ROOT} ${CMAKE_SOURCE_DIR}/vcpkg
+      NO_DEFAULT_PATH
+    )
     if (NOT vcpkg_program)
       message(WARNING "Qt Creator: vcpkg executable not found. "
                       "Package manager auto-setup will be skipped. "