Link error while building Qt 5.1.1 on Linux

reddish

Hi all,

I am trying to build the 5.1.1 source tarball on Debian GNU/Linux, using g++ 4.8.2. The make step fails on a linker error:

make[5]: Entering directory /home/sidney/MyQt/qt-everywhere-opensource-src-5.1.1/qtbase/src/plugins/platforms/offscreen' rm -f libqoffscreen.so g++ -Wl,--no-undefined -Wl,-O1 -Wl,-rpath,/home/sidney/MyQt/root-5.1.1/lib -Wl,-rpath-link,/home/sidney/MyQt/qt-everywhere-opensource-src-5.1.1/qtbase/lib -shared -o libqoffscreen.so .obj/release-shared/main.o .obj/release-shared/qoffscreenintegration.o .obj/release-shared/qoffscreenwindow.o .obj/release-shared/qoffscreencommon.o .obj/release-shared/qoffscreenintegration_x11.o -L/home/sidney/MyQt/qt-everywhere-opensource-src-5.1.1/qtbase/lib -lQt5PlatformSupport -pthread -lgthread-2.0 -lglib-2.0 -lz -lQt5DBus -lQt5Gui -lQt5Core -lGL -lpthread .obj/release-shared/qoffscreenintegration_x11.o: In function QOffscreenX11GLXContext::~QOffscreenX11GLXContext()':
qoffscreenintegration_x11.cpp:(.text+0x7b): undefined reference to XDestroyWindow' .obj/release-shared/qoffscreenintegration_x11.o: In function QOffscreenX11GLXContext::makeCurrent(QPlatformSurface*)':
qoffscreenintegration_x11.cpp:(.text+0x129): undefined reference to XResizeWindow' qoffscreenintegration_x11.cpp:(.text+0x140): undefined reference to XSync'
.obj/release-shared/qoffscreenintegration_x11.o: In function createDummyWindow(QOffscreenX11Info*, XVisualInfo*) [clone .isra.7]': qoffscreenintegration_x11.cpp:(.text+0x1e9): undefined reference to XCreateColormap'
qoffscreenintegration_x11.cpp:(.text+0x276): undefined reference to XCreateWindow' qoffscreenintegration_x11.cpp:(.text+0x287): undefined reference to XFreeColormap'
.obj/release-shared/qoffscreenintegration_x11.o: In function QOffscreenX11Connection::QOffscreenX11Connection()': qoffscreenintegration_x11.cpp:(.text+0x2e1): undefined reference to XInitThreads'
qoffscreenintegration_x11.cpp:(.text+0x2fd): undefined reference to XOpenDisplay' .obj/release-shared/qoffscreenintegration_x11.o: In function QOffscreenX11Connection::~QOffscreenX11Connection()':
qoffscreenintegration_x11.cpp:(.text+0x358): undefined reference to XCloseDisplay' .obj/release-shared/qoffscreenintegration_x11.o: In function QOffscreenX11GLXContext::QOffscreenX11GLXContext(QOffscreenX11Info*, QOpenGLContext*)':
qoffscreenintegration_x11.cpp:(.text+0x462): undefined reference to qglx_findConfig(_XDisplay*, int, QSurfaceFormat const&, int)' qoffscreenintegration_x11.cpp:(.text+0x4b8): undefined reference to qglx_surfaceFormatFromGLXFBConfig(QSurfaceFormat*, _XDisplay*, __GLXFBConfigRec*, __GLXcontextRec*)'
qoffscreenintegration_x11.cpp:(.text+0x4f1): undefined reference to XFree' qoffscreenintegration_x11.cpp:(.text+0x522): undefined reference to qglx_findVisualInfo(_XDisplay*, int, QSurfaceFormat*)'
qoffscreenintegration_x11.cpp:(.text+0x579): undefined reference to XFree' .obj/release-shared/qoffscreenintegration_x11.o: In function QOffscreenX11Integration::createPlatformOpenGLContext(QOpenGLContext*) const':
qoffscreenintegration_x11.cpp:(.text+0x6fd): undefined reference to XCloseDisplay' .obj/release-shared/qoffscreenintegration_x11.o: In function QOffscreenX11Integration::~QOffscreenX11Integration()':
qoffscreenintegration_x11.cpp:(.text._ZN24QOffscreenX11IntegrationD2Ev[_ZN24QOffscreenX11IntegrationD5Ev]+0x20): undefined reference to XCloseDisplay' .obj/release-shared/qoffscreenintegration_x11.o: In function QOffscreenX11Integration::~QOffscreenX11Integration()':
qoffscreenintegration_x11.cpp:(.text._ZN24QOffscreenX11IntegrationD0Ev[_ZN24QOffscreenX11IntegrationD0Ev]+0x21): undefined reference to XCloseDisplay' collect2: error: ld returned 1 exit status make[5]: *** [../../../../plugins/platforms/libqoffscreen.so] Error 1 make[5]: Leaving directory /home/sidney/MyQt/qt-everywhere-opensource-src-5.1.1/qtbase/src/plugins/platforms/offscreen'
make[4]: *** [sub-offscreen-make_first] Error 2
make[4]: Leaving directory /home/sidney/MyQt/qt-everywhere-opensource-src-5.1.1/qtbase/src/plugins/platforms' make[3]: *** [sub-platforms-make_first] Error 2 make[3]: Leaving directory /home/sidney/MyQt/qt-everywhere-opensource-src-5.1.1/qtbase/src/plugins'
make[2]: *** [sub-plugins-make_first] Error 2
make[2]: Leaving directory /home/sidney/MyQt/qt-everywhere-opensource-src-5.1.1/qtbase/src' make[1]: *** [sub-src-make_first] Error 2 make[1]: Leaving directory /home/sidney/MyQt/qt-everywhere-opensource-src-5.1.1/qtbase'
make: *** [module-qtbase-make_first] Error 2

It seems that there is an actual dependency on Xlib that somehow fails to make it into the Makefile.

Is there an easy fix?

Sidney

sierdzio

Yes, you have missing dependencies. Please go through the list "here":http://qt-project.org/wiki/Building_Qt_5_from_Git it provides all apt-get instructions you need to run before compiling Qt.

reddish

Thank you, I will look into that.

However, shouldn't the configure script discover and report missing dependencies on my system?
As a long-time unix user, this is what I would expect.

As it is now, I have no easy way to find out exactly which library or header file is missing. The reported link error suggests that a few very basic symbols residing in libX11 cannot be found, but the libX11-dev package is installed on my system -- it's just that -lX11 is not included in the link line for some reason.

sierdzio

Indeed, problems with X should have been discovered by configure. Qt does check for a ton of things in configure, though, maybe it somehow failed on your particular setup.

I'm a bit surprised it's building the offscreen plugin. Are you passing any arcane switches to configure?

reddish

Hi sierdzo,

Nothing weird, I just pass "-prefix" and "-opensource" options.

Now that I installed a slew of xcb packages (I am puzzled why the Debian maintainers elected to split that up in 40-odd packages... but I digress), 5.1.1 builds without issue.

Buiding 5.2.0-beta1 succeeds without a hitch, and it also built earlier when the xcb*dev packages where not installed. So it may be that this particular dependency issue was solved between 5.1 and 5.2.

sierdzio

Could be, 5.2 brings in really a ton of updates. Anyway, I'm glad it helped you. Happy coding :)