FTBFS qtwebengine: missing -I for libxkbcommon

FAILED: obj/ui/events/keycodes/x11/x11_jumbo_1.o 
/home/tjmaciei/bin/g++ -MMD -MF obj/ui/events/keycodes/x11/x11_jumbo_1.o.d -DKEYCODES_X_IMPLEMENTATION -DUSE_UDEV -DUSE_AURA=1 -DUSE_NSS_CERTS=1 -DUSE_OZONE=1 -DTOOLKIT_QT -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -I. -Igen -I../../../../../../../src/qt/qt5/qtwebengine/src/3rdparty/chromium -Igen -Igen -Igen -Igen -Igen -I../../../../../../../src/qt/qt5/qtwebengine/src/3rdparty/chromium/third_party/boringssl/src/include -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -funwind-tables -fPIC -pipe -pthread -m64 -Wno-builtin-macro-redefined -D__DATE__= -D__TIME__= -D__TIMESTAMP__= -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wno-unused-local-typedefs -Wno-maybe-uninitialized -Wno-deprecated-declarations -fno-delete-null-pointer-checks -Wno-comments -Wno-packed-not-aligned -Wno-dangling-else -Wno-missing-field-initializers -Wno-unused-parameter -O2 -fno-ident -fdata-sections -ffunction-sections -fno-omit-frame-pointer -g0 -fvisibility=hidden -std=gnu++14 -Wno-narrowing -Wno-class-memaccess -Wno-attributes -Wno-class-memaccess -Wno-subobject-linkage -Wno-invalid-offsetof -Wno-return-type -Wno-deprecated-copy -fno-exceptions -fno-rtti -fvisibility-inlines-hidden -c gen/ui/events/keycodes/x11_jumbo_1.cc -o obj/ui/events/keycodes/x11/x11_jumbo_1.o
In file included from ../../../../../../../src/qt/qt5/qtwebengine/src/3rdparty/chromium/ui/events/keycodes/keyboard_code_conversion_xkb.h:12,
                 from ./../../../../../../../src/qt/qt5/qtwebengine/src/3rdparty/chromium/ui/events/keycodes/keyboard_code_conversion_x.cc:17,
                 from gen/ui/events/keycodes/x11_jumbo_1.cc:5:
../../../../../../../src/qt/qt5/qtwebengine/src/3rdparty/chromium/ui/events/keycodes/xkb_keysym.h:15:10: fatal error: xkbcommon/xkbcommon.h: No such file or directory
   15 | #include <xkbcommon/xkbcommon.h>
      |          ^~~~~~~~~~~~~~~~~~~~~~~

 ls -l /usr/include/libxkbcommon/xkbcommon/xkbcommon.h 
-rw-r--r-- 1 root root 62834 Jan 18 13:13 /usr/include/libxkbcommon/xkbcommon/xkbcommon.h

$ grep xkbcommon config.cache 
cache.xkbcommon._KEYS_ = result msgs source sources.0.libs sources.0.includedir sources.0.cflags sources.0.version sources.0.export
cache.xkbcommon.result = true
cache.xkbcommon.msgs = "Trying source 0 (type pkgConfig) of library xkbcommon ..." "+ /usr/bin/pkg-config --exists --silence-errors xkbcommon \'>=\' 0.5.0" "+ /usr/bin/pkg-config --modversion xkbcommon \'>=\' 0.5.0" "> 0.10.0" "+ /usr/bin/pkg-config --libs-only-L xkbcommon \'>=\' 0.5.0" "+ /usr/bin/pkg-config --libs-only-l xkbcommon \'>=\' 0.5.0" "> -lxkbcommon " "+ /usr/bin/pkg-config --cflags xkbcommon \'>=\' 0.5.0" "> -I/usr/include/libxkbcommon " "+ cd /home/tjmaciei/obj/qt/qt5-release/config.tests/xkbcommon && /home/tjmaciei/obj/qt/qt5-release/qtbase/bin/qmake \"CONFIG -= qt debug_and_release app_bundle lib_bundle\" \"CONFIG += shared warn_off console single_arch\" \'QMAKE_USE += xkbcommon\' \'QMAKE_LIBS_XKBCOMMON = -lxkbcommon\' \'QMAKE_INCDIR_XKBCOMMON = /usr/include/libxkbcommon\' /home/tjmaciei/obj/qt/qt5-release/config.tests/xkbcommon" "+ cd /home/tjmaciei/obj/qt/qt5-release/config.tests/xkbcommon && MAKEFLAGS= /usr/bin/gmake" "> g++ -c -pipe -pipe -march=skylake -O3 -g1 -w -fPIC  -I. -isystem /usr/include/libxkbcommon -I/home/tjmaciei/src/qt/qt5/qtbase/mkspecs/linux-g++-optimised -o main.o main.cpp" "> g++ -pipe -march=skylake -Wl,-O1 -Wl,--as-needed -Wl,-z,relro -Wl,--enable-new-dtags -fuse-linker-plugin -Wl,-O1 -o xkbcommon main.o   -lxkbcommon   " " => source accepted."
cache.xkbcommon.source = 0
cache.xkbcommon.sources.0.libs = -lxkbcommon
cache.xkbcommon.sources.0.includedir = /usr/include/libxkbcommon
cache.xkbcommon.sources.0.cflags = "-I/usr/include/libxkbcommon "
cache.xkbcommon.sources.0.version = 0.10.0
cache.xkbcommon.sources.0.export = 
cache.xkbcommon_x11._KEYS_ = result msgs source sources.0.libs sources.0.includedir sources.0.cflags sources.0.version sources.0.export
cache.xkbcommon_x11.result = true
cache.xkbcommon_x11.msgs = "Trying source 0 (type pkgConfig) of library xkbcommon_x11 ..." "+ /usr/bin/pkg-config --exists --silence-errors xkbcommon-x11" "+ /usr/bin/pkg-config --modversion xkbcommon-x11" "> 0.10.0" "+ /usr/bin/pkg-config --libs-only-L xkbcommon-x11" "+ /usr/bin/pkg-config --libs-only-l xkbcommon-x11" "> -lxkbcommon-x11 -lxkbcommon " "+ /usr/bin/pkg-config --cflags xkbcommon-x11" "> -I/usr/include/libxkbcommon " "+ cd /home/tjmaciei/obj/qt/qt5-release/config.tests/xkbcommon_x11 && /home/tjmaciei/obj/qt/qt5-release/qtbase/bin/qmake \"CONFIG -= qt debug_and_release app_bundle lib_bundle\" \"CONFIG += shared warn_off console single_arch\" \'QMAKE_USE += xkbcommon_x11\' \'QMAKE_LIBS_XKBCOMMON_X11 = -lxkbcommon-x11 -lxkbcommon\' \'QMAKE_INCDIR_XKBCOMMON_X11 = /usr/include/libxkbcommon\' /home/tjmaciei/obj/qt/qt5-release/config.tests/xkbcommon_x11" "+ cd /home/tjmaciei/obj/qt/qt5-release/config.tests/xkbcommon_x11 && MAKEFLAGS= /usr/bin/gmake" "> g++ -c -pipe -pipe -march=skylake -O3 -g1 -w -fPIC  -I. -isystem /usr/include/libxkbcommon -I/home/tjmaciei/src/qt/qt5/qtbase/mkspecs/linux-g++-optimised -o main.o main.cpp" "> g++ -pipe -march=skylake -Wl,-O1 -Wl,--as-needed -Wl,-z,relro -Wl,--enable-new-dtags -fuse-linker-plugin -Wl,-O1 -o xkbcommon_x11 main.o   -lxkbcommon-x11 -lxkbcommon   " " => source accepted."
cache.xkbcommon_x11.source = 0
cache.xkbcommon_x11.sources.0.libs = -lxkbcommon-x11 -lxkbcommon
cache.xkbcommon_x11.sources.0.includedir = /usr/include/libxkbcommon
cache.xkbcommon_x11.sources.0.cflags = "-I/usr/include/libxkbcommon "
cache.xkbcommon_x11.sources.0.version = 0.10.0
cache.xkbcommon_x11.sources.0.export = 
cache.gtk3.msgs = "Trying source 0 (type pkgConfig) of library gtk3 ..." "+ /usr/bin/pkg-config --exists --silence-errors gtk+-3.0 \'>=\' 3.6" "+ /usr/bin/pkg-config --modversion gtk+-3.0 \'>=\' 3.6" "> 3.24.18" "+ /usr/bin/pkg-config --libs-only-L gtk+-3.0 \'>=\' 3.6" "+ /usr/bin/pkg-config --libs-only-l gtk+-3.0 \'>=\' 3.6" "> -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -lharfbuzz -latk-1.0 -lcairo-gobject -lcairo -lgdk_pixbuf-2.0 -lgio-2.0 -lgobject-2.0 -lglib-2.0 " "+ /usr/bin/pkg-config --cflags gtk+-3.0 \'>=\' 3.6" "> -I/usr/include/gtk-3.0 -I/usr/include/pango-1.0 -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/harfbuzz -I/usr/include/fribidi -I/usr/include/freetype2 -I/usr/include/uuid -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/libpng16 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/wayland -I/usr/include/libxkbcommon -I/usr/include/atk-1.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/dbus-1.0 -I/usr/lib64/dbus-1.0/include -I/usr/include/at-spi-2.0 -pthread " "Note: Dropped compiler flags \'-pthread\'." " => source accepted."
cache.gtk3.sources.0.includedir = /usr/include/gtk-3.0 /usr/include/pango-1.0 /usr/include/glib-2.0 /usr/lib64/glib-2.0/include /usr/include/harfbuzz /usr/include/fribidi /usr/include/freetype2 /usr/include/uuid /usr/include/cairo /usr/include/pixman-1 /usr/include/libpng16 /usr/include/gdk-pixbuf-2.0 /usr/include/libmount /usr/include/blkid /usr/include/gio-unix-2.0 /usr/include/wayland /usr/include/libxkbcommon /usr/include/atk-1.0 /usr/include/at-spi2-atk/2.0 /usr/include/dbus-1.0 /usr/lib64/dbus-1.0/include /usr/include/at-spi-2.0
cache.gtk3.sources.0.cflags = "-I/usr/include/gtk-3.0 -I/usr/include/pango-1.0 -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/harfbuzz -I/usr/include/fribidi -I/usr/include/freetype2 -I/usr/include/uuid -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/libpng16 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/wayland -I/usr/include/libxkbcommon -I/usr/include/atk-1.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/dbus-1.0 -I/usr/lib64/dbus-1.0/include -I/usr/include/at-spi-2.0 -pthread "
cache.webengine-xkbcommon._KEYS_ = result msgs source sources.0.libs sources.0.includedir sources.0.cflags sources.0.version sources.0.export
cache.webengine-xkbcommon.result = true
cache.webengine-xkbcommon.msgs = "Trying source 0 (type pkgConfig) of library webengine-xkbcommon ..." "+ /usr/bin/pkg-config --exists --silence-errors xkbcommon" "+ /usr/bin/pkg-config --modversion xkbcommon" "> 0.10.0" "+ /usr/bin/pkg-config --libs-only-L xkbcommon" "+ /usr/bin/pkg-config --libs-only-l xkbcommon" "> -lxkbcommon " "+ /usr/bin/pkg-config --cflags xkbcommon" "> -I/usr/include/libxkbcommon " " => source accepted."
cache.webengine-xkbcommon.source = 0
cache.webengine-xkbcommon.sources.0.libs = -lxkbcommon
cache.webengine-xkbcommon.sources.0.includedir = /usr/include/libxkbcommon
cache.webengine-xkbcommon.sources.0.cflags = "-I/usr/include/libxkbcommon "
cache.webengine-xkbcommon.sources.0.version = 0.10.0
cache.webengine-xkbcommon.sources.0.export =