When I try to build Qt 4.8.6 on my Ubuntu 14.04 LTS (64 bits), by typing “sudo make install” I get a lot of errors like the following:
../../JavaScriptCore/wtf/PassOwnPtr.h: In member function ‘bool WTF::PassOwnPtr<T>::operator!=(const WTF::OwnPtr<U>&)’:
../../JavaScriptCore/wtf/Assertions.h:326:47: warning: typedef ‘dummyOwnPtrs_should_never_be_equal’ locally defined but not used [-Wunused-local-typedefs]
#define COMPILE_ASSERT(exp, name) typedef int dummy##name [(exp) ? 1 : -1]
^
../../JavaScriptCore/wtf/PassOwnPtr.h:98:66: note: in expansion of macro ‘COMPILE_ASSERT’
template<typename U> bool operator!=(const OwnPtr<U>&) { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; }
^
To put everything into context, here’s my sequence of problems:
I have a Qt project working fine in Qt Creator with Qt 5 and I wanted to make it backward-compatible for Qt 4, but I discovered my Qt 4.8.6 kit configuration that the Qt version was invalid.
I clicked Manage to sort that out. There was written “qmake location: /usr/bin/qmake-qt4” and “Qt version is not properly installed, please run make install”.
I found on the Internet that this error could mean some Qt variables are not properly configured, like QT_INSTALL_BINS or QT_INSTALL_HEADERS. Indeed, my QT_INSTALL_HEADERS was pointing to /usr/include/qt4 which doesn’t exist.
I downloaded the Qt 4.8.6 source and ran the install sequence: configure, sudo make, sudo make install, then I got the error mentioned above.
I found a bug report with similar errors, saying that it worked with gcc-4.7 but not with gcc-4.8 anymore. So I installed gcc-4.8, and tried again, with no luck.
How can I get a functioning Qt 4?
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