--- /dev/null
+gn is modified (e.g. create_pri_file), so cannot use system version.
+At least link it dynamically.
+--- qtwebengine-everywhere-src-5.15.2/src/buildtools/gn.pro.orig 2020-11-07 02:22:36.000000000 +0100
++++ qtwebengine-everywhere-src-5.15.2/src/buildtools/gn.pro 2021-01-01 09:01:29.391918979 +0100
+@@ -19,6 +19,7 @@
+ gn_bootstrap = $$system_path($$absolute_path(gn/build/gen.py, $$src_3rd_party_dir))
+
+ gn_gen_args = --no-last-commit-position --out-path $$out_path \
++ --no-static-libstdc++ \
+ --cc \"$$which($$QMAKE_CC)\" --cxx \"$$which($$QMAKE_CXX)\" \
+ --ld \"$$which($$QMAKE_LINK)\"
+