Constant crashes all the time

I'm getting constant crashes which render any qt5 web browser almost useless. Tried with QtTestBrowser and QupZilla-qt5. Crashes occur upon pasting something into input field, or by copying text, sometimes even selecting text can cause crash.

Arch Linux, Qt compiled with:

-confirm-license -opensource \
-prefix /usr \
-bindir /usr/lib/qt/bin \
-docdir /usr/share/doc/qt \
-headerdir /usr/include/qt \
-archdatadir /usr/lib/qt \
-datadir /usr/share/qt \
-sysconfdir /etc/xdg \
-examplesdir /usr/share/doc/qt/examples \
plugin-sql

\
-system-harfbuzz \
-system-sqlite \
-openssl-linked \
-nomake examples \
-no-rpath \
-optimized-qmake \
-dbus-linked \
-reduce-relocations