fails to build on Linux

[Kolcha]

Ubuntu 18.04 (bionic), amd64, build on Travis CI

../../../3rdparty/QHotkey/QHotkey/qhotkey_x11.cpp: In member function ‘virtual bool QHotkeyPrivateX11::nativeEventFilter(const QByteArray&, void*, long int*)’:
../../../3rdparty/QHotkey/QHotkey/qhotkey_x11.cpp:88:9: error: ‘class QHotkeyPrivateX11’ has no member named ‘releaseTimer’; did you mean ‘deleteLater’?
   this->releaseTimer = timer;
         ^~~~~~~~~~~~
         deleteLater
../../../3rdparty/QHotkey/QHotkey/qhotkey_x11.cpp: In constructor ‘QHotkeyPrivateX11::HotkeyErrorHandler::HotkeyErrorHandler()’:
../../../3rdparty/QHotkey/QHotkey/qhotkey_x11.cpp:220:2: error: invalid use of non-static data member ‘QHotkeyPrivateX11::prevHandler’
  prevHandler = XSetErrorHandler(&HotkeyErrorHandler::handleError);
  ^~~~~~~~~~~
../../../3rdparty/QHotkey/QHotkey/qhotkey_x11.cpp:32:16: note: declared here
  XErrorHandler prevHandler;
                ^~~~~~~~~~~
../../../3rdparty/QHotkey/QHotkey/qhotkey_x11.cpp: In destructor ‘QHotkeyPrivateX11::HotkeyErrorHandler::~HotkeyErrorHandler()’:
../../../3rdparty/QHotkey/QHotkey/qhotkey_x11.cpp:225:19: error: invalid use of non-static data member ‘QHotkeyPrivateX11::prevHandler’
  XSetErrorHandler(prevHandler);
                   ^~~~~~~~~~~
../../../3rdparty/QHotkey/QHotkey/qhotkey_x11.cpp:32:16: note: declared here
  XErrorHandler prevHandler;
                ^~~~~~~~~~~
Makefile:583: recipe for target 'qhotkey_x11.o' failed
make[2]: *** [qhotkey_x11.o] Error 1

library is a part of app, qhotkey.pri is included
full build output can be found here, it has some highlight, so it is easier to read

[mostvexingparse]

had the same issue, it looks like #32 broke the build on linux

[Skycoder42]

I'll take a look at it this weekend