Broken CSS on a fresh build

[njv1995]

Hi Folks,

I'm having this weird issue with example projects after building QT on CentOS 7.3.

Has anyone encountered this issue?
Config options

-prefix ./amd64
-release
-commercial
-confirm-license
-shared
-platform linux-g++-64
-xcb
-xcb-xlib
-no-bundled-xcb-xinput
-no-rpath
-fontconfig
-no-reduce-relocations
-no-cups
-no-mtdev
-no-libudev
-no-egl
-no-gbm
-no-gtk
-nomake examples
-plugin-sql-mysql
-plugin-sql-sqlite
-plugin-sql-odbc
-icu
-skip qtgamepad
-I /opt/openssl-1.1.1a/include
-L /opt/openssl-1.1.1a/lib
-I /opt/icu/include
-L /opt/icu/lib

Build type: linux-g++-64 (x86_64, CPU features: mmx sse sse2)
Compiler: gcc 9.2.0
Configuration: sse2 aesni sse3 ssse3 sse4_1 sse4_2 avx avx2 avx512f avx512bw avx512cd avx512dq avx512er avx512ifma avx512pf avx512vbmi avx512vl compile_examples enable_new_dtags f16c largefile precompile_header rdrnd rdseed shani x86SimdAlways shared shared release c++11 c++14 c++17 c++1z concurrent dbus reduce_exports stl
Build options:
  Mode ................................... release
  Optimize release build for size ........ no
  Building shared libraries .............. yes
  Using C standard ....................... C11
  Using C++ standard ..................... C++17
  Using ccache ........................... no
  Using new DTAGS ........................ yes
  Relocatable ............................ yes
  Using precompiled headers .............. yes
  Using LTCG ............................. no
  Target compiler supports:
    SSE .................................. SSE2 SSE3 SSSE3 SSE4.1 SSE4.2
    AVX .................................. AVX AVX2
    AVX512 ............................... F ER CD PF DQ BW VL IFMA VBMI
    Other x86 ............................ AES F16C RDRAND SHA
    Intrinsics without -mXXX option ...... yes
  Build parts ............................ libs tools
Qt modules and options:
  Qt Concurrent .......................... yes
  Qt D-Bus ............................... yes
  Qt D-Bus directly linked to libdbus .... yes
  Qt Gui ................................. yes
  Qt Network ............................. yes
  Qt Sql ................................. yes
  Qt Testlib ............................. yes
  Qt Widgets ............................. yes
  Qt Xml ................................. yes
Support enabled for:
  Using pkg-config ....................... yes
  udev ................................... no
  Using system zlib ...................... yes
  Zstandard support ...................... no
Qt Core:
  DoubleConversion ....................... yes
    Using system DoubleConversion ........ no
  GLib ................................... yes
  iconv .................................. no
  ICU .................................... yes
  Built-in copy of the MIME database ..... yes
  Tracing backend ........................ <none>
  Logging backends:
    journald ............................. no
    syslog ............................... no
    slog2 ................................ no
  PCRE2 .................................. yes
    Using system PCRE2 ................... no
Qt Network:
  getifaddrs() ........................... yes
  IPv6 ifname ............................ yes
  libproxy ............................... no
  Linux AF_NETLINK ....................... yes
  OpenSSL ................................ yes
    Qt directly linked to OpenSSL ........ no
  OpenSSL 1.1 ............................ yes
  DTLS ................................... yes
  OCSP-stapling .......................... yes
  SCTP ................................... no
  Use system proxies ..................... yes
  GSSAPI ................................. yes
Qt Gui:
  Accessibility .......................... yes
  FreeType ............................... yes
    Using system FreeType ................ yes
  HarfBuzz ............................... yes
    Using system HarfBuzz ................ yes
  Fontconfig ............................. yes
  Image formats:
    GIF .................................. yes
    ICO .................................. yes
    JPEG ................................. yes
      Using system libjpeg ............... yes
    PNG .................................. yes
      Using system libpng ................ yes
  Text formats:
    HtmlParser ........................... yes
    CssParser ............................ yes
    OdfWriter ............................ yes
    MarkdownReader ....................... yes
      Using system libmd4c ............... no
    MarkdownWriter ....................... yes
  EGL .................................... no
  OpenVG ................................. no
  OpenGL:
    Desktop OpenGL ....................... yes
    OpenGL ES 2.0 ........................ no
    OpenGL ES 3.0 ........................ no
    OpenGL ES 3.1 ........................ no
    OpenGL ES 3.2 ........................ no
  Vulkan ................................. no
  Session Management ..................... yes
Features used by QPA backends:
  evdev .................................. yes
  libinput ............................... no
  INTEGRITY HID .......................... no
  mtdev .................................. no
  tslib .................................. no
  xkbcommon .............................. yes
  X11 specific:
    XLib ................................. yes
    XCB Xlib ............................. yes
    EGL on X11 ........................... no
    xkbcommon-x11 ........................ yes
QPA backends:
  DirectFB ............................... no
  EGLFS .................................. no
  LinuxFB ................................ yes
  VNC .................................... yes
  XCB:
    Using system-provided xcb-xinput ..... yes
    Native painting (experimental) ....... no
    GL integrations:
      GLX Plugin ......................... yes
        XCB GLX .......................... yes
      EGL-X11 Plugin ..................... no
Qt Sql:
  SQL item models ........................ yes
Qt Widgets:
  GTK+ ................................... no
  Styles ................................. Fusion Windows
Qt PrintSupport:
  CUPS ................................... no
Qt Sql Drivers:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. yes
  OCI (Oracle) ........................... no
  ODBC ................................... yes
  PostgreSQL ............................. yes
  SQLite2 ................................ no
  SQLite ................................. yes
    Using system provided SQLite ......... no
  TDS (Sybase) ........................... no
Qt Testlib:
  Tester for item models ................. yes
Serial Port:
  ntddmodm ............................... no
Qt SerialBus:
  Socket CAN ............................. yes
  Socket CAN FD .......................... yes
  SerialPort Support ..................... yes
Further Image Formats:
  JasPer ................................. no
  MNG .................................... yes
  TIFF ................................... yes
    Using system libtiff ................. yes
  WEBP ................................... yes
    Using system libwebp ................. no
Qt QML:
  QML network support .................... yes
  QML debugging and profiling support .... yes
  QML just-in-time compiler .............. yes
  QML sequence object .................... yes
  QML XML http request ................... yes
  QML Locale ............................. yes
Qt QML Models:
  QML list model ......................... yes
  QML delegate model ..................... yes
Qt Quick:
  Direct3D 12 ............................ no
  AnimatedImage item ..................... yes
  Canvas item ............................ yes
  Support for Qt Quick Designer .......... yes
  Flipable item .......................... yes
  GridView item .......................... yes
  ListView item .......................... yes
  TableView item ......................... yes
  Path support ........................... yes
  PathView item .......................... yes
  Positioner items ....................... yes
  Repeater item .......................... yes
  ShaderEffect item ...................... yes
  Sprite item ............................ yes
QtQuick3D:
  Assimp ................................. yes
  System Assimp .......................... no
Qt Scxml:
  ECMAScript data model for QtScxml ...... yes
Qt 3D:
  Assimp ................................. yes
  System Assimp .......................... no
  Output Qt3D GL traces .................. no
  Use SSE2 instructions .................. yes
  Use AVX2 instructions .................. no
  Aspects:
    Render aspect ........................ yes
    Input aspect ......................... yes
    Logic aspect ......................... yes
    Animation aspect ..................... yes
    Extras aspect ........................ yes
Qt 3D Renderers:
  OpenGL Renderer ........................ yes
  RHI Renderer ........................... no
Qt 3D GeometryLoaders:
  Autodesk FBX ........................... no
Qt Wayland Drivers:
  EGL .................................... no
  Raspberry Pi ........................... no
  XComposite EGL ......................... no
  XComposite GLX ......................... yes
  DRM EGL ................................ no
  libhybris EGL .......................... no
  Linux dma-buf server buffer integration . no
  Vulkan-based server buffer integration . no
  Shm emulation server buffer integration . yes
Qt Wayland Client Shell Integrations:
  xdg-shell .............................. yes
  xdg-shell unstable v5 (deprecated) ..... yes
  xdg-shell unstable v6 .................. yes
  ivi-shell .............................. yes
  wl-shell (deprecated) .................. yes
Qt Wayland Client ........................ yes
Qt Wayland Compositor .................... yes
Qt Wayland Compositor Layer Plugins:
  VSP2 hardware layer integration ........ no
Qt Bluetooth:
  BlueZ .................................. no
  BlueZ Low Energy ....................... no
  Linux Crypto API ....................... no
  Native Win32 Bluetooth ................. no
  WinRT Bluetooth API (desktop & UWP) .... no
  WinRT advanced bluetooth low energy API (desktop & UWP) . no
Qt Sensors:
  sensorfw ............................... no
Qt Quick Controls 2:
  Styles ................................. Default Fusion Imagine Material Universal
Qt Quick Templates 2:
  Hover support .......................... yes
  Multi-touch support .................... yes
Qt Positioning:
  Gypsy GPS Daemon ....................... no
  WinRT Geolocation API .................. no
Qt Location:
  Qt.labs.location experimental QML plugin . yes
  Geoservice plugins:
    OpenStreetMap ........................ yes
    HERE ................................. yes
    Esri ................................. yes
    Mapbox ............................... yes
    MapboxGL ............................. yes
    Itemsoverlay ......................... yes
QtXmlPatterns:
  XML schema support ..................... yes
Qt Multimedia:
  ALSA ................................... yes
  GStreamer 1.0 .......................... yes
  GStreamer 0.10 ......................... no
  Video for Linux ........................ yes
  OpenAL ................................. no
  PulseAudio ............................. yes
  Resource Policy (libresourceqt5) ....... no
  Windows Audio Services ................. no
  DirectShow ............................. no
  Windows Media Foundation ............... no
Qt TextToSpeech:
  Flite .................................. no
  Flite with ALSA ........................ no
  Speech Dispatcher ...................... no
Qt Tools:
  Qt Assistant ........................... yes
  Qt Designer ............................ yes
  Qt Distance Field Generator ............ yes
  kmap2qmap .............................. yes
  Qt Linguist ............................ yes
  Mac Deployment Tool .................... no
  makeqpf ................................ yes
  pixeltool .............................. yes
  qdbus .................................. yes
  qev .................................... yes
  Qt Attributions Scanner ................ yes
  qtdiag ................................. yes
  qtpaths ................................ yes
  qtplugininfo ........................... yes
  Windows deployment tool ................ no
  WinRT Runner Tool ...................... no
Qt Tools:
  QDoc ................................... yes
Qt WebEngine Build Tools:
  Use System Ninja ....................... yes
  Jumbo Build Merge Limit ................ 8
  Developer build ........................ no
  Sanitizer .............................. no
  QtWebEngine required system libraries:
    fontconfig ........................... yes
    dbus ................................. yes
    nss .................................. yes
    khr .................................. yes
    glibc ................................ yes
  QtWebEngine required system libraries for qpa-xcb:
    x11 .................................. yes
    libdrm ............................... yes
    xcomposite ........................... yes
    xcursor .............................. yes
    xi ................................... yes
    xproto (glproto) ..................... yes
    xtst ................................. yes
    xkbfile .............................. yes
  Optional system libraries used:
    re2 .................................. no
    icu .................................. no
    libwebp, libwebpmux and libwebpdemux . no
    opus ................................. no
    ffmpeg ............................... no
    libvpx ............................... no
    snappy ............................... no
    glib ................................. yes
    zlib ................................. yes
    minizip .............................. no
    libevent ............................. no
    libxml2 and libxslt .................. no
    lcms2 ................................ no
    png .................................. no
    JPEG ................................. no
    harfbuzz ............................. no
    freetype ............................. yes
Qt WebEngineCore:
  Embedded build ......................... no
  Full debug information ................. no
  Pepper Plugins ......................... yes
  Printing and PDF ....................... yes
  Proprietary Codecs ..................... no
  Spellchecker ........................... yes
  Native Spellchecker .................... no
  WebRTC ................................. yes
  PipeWire over GIO ...................... no
  Geolocation ............................ yes
  WebChannel support ..................... yes
  Kerberos Authentication ................ no
  Extensions ............................. yes
  Support qpa-xcb ........................ yes
  Use ALSA ............................... yes
  Use PulseAudio ......................... yes
Qt WebEngineQml:
  Support Qt WebEngine Qml ............... yes
  UI Delegates ........................... yes
  Test Support ........................... no
Qt WebEngineWidgets:
  Support Qt WebEngine Widgets ........... yes
Qt PDF:
  Support V8 ............................. no
  Support XFA ............................ no
  Support XFA-BMP ........................ no
  Support XFA-GIF ........................ no
  Support XFA-PNG ........................ no
  Support XFA-TIFF ....................... no
  Bitcode support ........................ no
  Use static runtime ..................... no
Qt PDF Widgets:
  Support Qt PDF Widgets ................. yes

[njv1995]

I have finally found out what was the cause.
In my PATH variable /usr/local/bin came before /usr/bin folder where Bison was pointing to version is 2.4, instead of /usr/bin's 2.7.
Strangely QT didn't give any errors and Bison test has passed successfully with 2.4 version. After pointing to the newer 2.7 version everything worked fine.