Syntax matters.

python-qt5.spec

@@ -284,7 +284,7 @@ pushd %{_target_platform}
   %{!?with_python3:--no-qsci-api}%{?with_python3:--qsci-api --qsci-api-destdir=%{_qt5_datadir}/qsci} \
   --verbose \
   --sip-incdir %{_prefix}/include/python%{python2_version}/ \
-  --dbus=%{_includedir}/dbus-1.0/dbus/ \
+  --dbus %{_includedir}/dbus-1.0/dbus/ \
   QMAKE_CFLAGS_RELEASE="%{optflags}" \
   QMAKE_CXXFLAGS_RELEASE="%{optflags}" \
   QMAKE_LFLAGS_RELEASE="%{?__global_ldflags}"
@@ -307,7 +307,7 @@ pushd %{_target_platform}-python3
   %{?py3_sipdir:--sipdir=%{py3_sipdir}} \
   --verbose \
   --sip-incdir %{_prefix}/include/python%{python3_version}m/ \
-  --dbus=%{_includedir}/dbus-1.0/dbus/ \
+  --dbus %{_includedir}/dbus-1.0/dbus/ \
   QMAKE_CFLAGS_RELEASE="%{optflags}" \
   QMAKE_CXXFLAGS_RELEASE="%{optflags}" \
   QMAKE_LFLAGS_RELEASE="%{?__global_ldflags}"