undefined reference to `QwtPlot::qt_metacall(QMetaObject::Call, int, void**)'

[Mr_Grieves]

The qwt library is in my linking path, but it does seem to be a problem with the linker.

Removing Q_OBJECT macro from the histPlot.h header didn't help. Let me know if theres anything else that would be helpful to see -- I'd really like to resolve this quickly

[Mr_Grieves]

The error changes a bit when Q_OBJECT is removed:

histPlot.o:(.rodata._ZTV8HistPlot[vtable for HistPlot]+0x18): undefined reference to `QwtPlot::qt_metacast(char const*)'
histPlot.o:(.rodata._ZTV8HistPlot[vtable for HistPlot]+0x20): undefined reference to `QwtPlot::qt_metacall(QMetaObject::Call, int, void**)'
collect2: ld returned 1 exit status
make: *** [timeClock] Error 1

histPlot.o:(.rodata._ZTV8HistPlot[vtable for HistPlot]+0x18): undefined reference to `QwtPlot::qt_metacast(char const*)'
histPlot.o:(.rodata._ZTV8HistPlot[vtable for HistPlot]+0x20): undefined reference to `QwtPlot::qt_metacall(QMetaObject::Call, int, void**)'
collect2: ld returned 1 exit status
make: *** [timeClock] Error 1

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[Mr_Grieves]

Got it working. Updated to the latest Qwt and linking completes.

[mendes]

I have the same problem, only I'm already using qwt-5.2.0 so I can't update.
This project works on another computer not mine. I can compile and run qwt examples
Any ideas what the problem might be?

[jord]

I don't have a build environment handy to verify this advice, but the error looks familiar...

Make sure QWT_DLL is defined in your compiler flags.

[mendes]

I solved this problem by changing the install dir of qwt to /usr, this in linux

[Uwe]

I solved this problem by changing the install dir of qwt to /usr, this in linux

Whatever solved the problem in your particular situation - changing the install dir to /usr has absolutely nothing to do with it.

Uwe

[barrygp]

I receive the same error when I changed qwt from shared lib to static library under linux. any idea what may be the issue? thanks.