depends: Fix cross-compiling qt package from macOS to Windows

Author: hebasto

depends/packages/qt.mk

@@ -190,6 +190,14 @@ ifneq ($(host),$(build))
 $(package)_cmake_opts += -DCMAKE_SYSTEM_NAME=$($(host_os)_cmake_system_name)
 $(package)_cmake_opts += -DCMAKE_SYSTEM_VERSION=$($(host_os)_cmake_system_version)
 $(package)_cmake_opts += -DCMAKE_SYSTEM_PROCESSOR=$(host_arch)
+# Native packages cannot be used during cross-compiling. However,
+# Qt still unconditionally tries to find them, which causes issues
+# in some cases, such as when cross-compiling from macOS to Windows.
+# Explicitly disable this unnecessary Qt behaviour.
+$(package)_cmake_opts += -DCMAKE_DISABLE_FIND_PACKAGE_Libb2=TRUE
+$(package)_cmake_opts += -DCMAKE_DISABLE_FIND_PACKAGE_WrapSystemDoubleConversion=TRUE
+$(package)_cmake_opts += -DCMAKE_DISABLE_FIND_PACKAGE_WrapSystemMd4c=TRUE
+$(package)_cmake_opts += -DCMAKE_DISABLE_FIND_PACKAGE_WrapZSTD=TRUE
 endif
 ifeq ($(host_os),darwin)
 $(package)_cmake_opts += -DCMAKE_INSTALL_NAME_TOOL=true