[LyX/master] Amend 771f30e9 for cmake

[Enrico Forestieri]

commit e8b366d4d6a5264200aa2a2654a5f3a2cd3652f3
Author: Enrico Forestieri <forenr at lyx.org>
Date:   Sun Oct 17 19:17:01 2021 +0200

    Amend 771f30e9 for cmake
---
 src/frontends/qt/CMakeLists.txt |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/src/frontends/qt/CMakeLists.txt b/src/frontends/qt/CMakeLists.txt
index 9709d71..38f3301 100644
--- a/src/frontends/qt/CMakeLists.txt
+++ b/src/frontends/qt/CMakeLists.txt
@@ -31,6 +31,10 @@ include_directories(
 	${QT_INCLUDES}
 	${CMAKE_CURRENT_BINARY_DIR})
 
+if (LYX_USE_QT MATCHES "QT6")
+        include_directories(${Qt6Gui_PRIVATE_INCLUDE_DIRS})
+endif()
+
 if(LYX_MERGE_FILES)
 	lyx_const_touched_files(_allinone frontends_qt_sources)
 	set(depends_moc_uic ${frontends_qt_headers} ${ui_files})