More travis fixes

.travis/install.sh

@@ -3,6 +3,7 @@
 set -e
 
 sudo apt-get install -y \
+    g++-multilib \
     pkg-config \
     pyqt5-dev-tools \
     python3-pyqt5.qtsvg \

.travis/script-win32.sh

@@ -12,6 +12,7 @@ export CFLAGS="${_FLAGS}"
 export CXXFLAGS="${_FLAGS}"
 export PATH=/opt/mingw32/${_PREFIX}/bin:/opt/mingw32/bin:${PATH}
 export PKG_CONFIG_PATH=/opt/mingw32/lib/pkgconfig:${PKG_CONFIG_PATH}
+export CROSS_COMPILING=true
 
 # Start clean
 make distclean >/dev/null

.travis/script-win64.sh

@@ -12,6 +12,7 @@ export CFLAGS="${_FLAGS}"
 export CXXFLAGS="${_FLAGS}"
 export PATH=/opt/mingw64/${_PREFIX}/bin:/opt/mingw64/bin:${PATH}
 export PKG_CONFIG_PATH=/opt/mingw64/lib/pkgconfig:${PKG_CONFIG_PATH}
+export CROSS_COMPILING=true
 
 # Start clean
 make distclean >/dev/null