Re: Octave 6.0.90 build failure on macOS 10.13 against Qt 5.15.1: link error on missing Qt symbols

On 9/16/20 9:00 AM, Markus Mützel wrote:
> Am 16. September 2020 um 14:39 Uhr schrieb "Andrew Janke":
>> Hi folks,
>>
>> I tried building the Octave 6.0.90 release candidate on macOS 10.13
>> against the new Qt 5.15.1 LTS release, and it's failing at the link
>> stage with this error:
>>
>> libtool: link: clang++ -std=gnu++11 -dynamiclib  -o
>> libgui/.libs/liboctgui.6.dylib
>> libgui/.libs/liboctgui_la-liboctgui-build-info.o
>> -Wl,-force_load,libgui/qterminal/.libs/libqterminal.a
>> -Wl,-force_load,libgui/graphics/.libs/libgraphics.a
>> -Wl,-force_load,libgui/src/.libs/libgui-src.a
>> -L/Applications/Octave-6.0.90.app/Contents/Resources/usr/opt/hdf5/lib
>> -L/Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/graphicsmagick/1.3.35/lib
>> -L/Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/fftw/3.3.8_2/lib
>> -L/Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/arpack/3.7.0_5/libexec/lib
>> -L/Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/pcre/8.44/lib
>> -L/Applications/Octave-6.0.90.app/Contents/Resources/usr/opt/qscintilla2-octave-app/lib
>> libinterp/.libs/liboctinterp.dylib
>> -L/Applications/Octave-6.0.90.app/Contents/Resources/usr/opt/openblas/lib
>> -L/Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/gcc/10.2.0/lib/gcc/10/gcc/x86_64-apple-darwin17/10.2.0
>> -L/Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/gcc/10.2.0/lib/gcc/10/gcc/x86_64-apple-darwin17/10.2.0/../../..
>> -L/Applications/Octave-6.0.90.app/Contents/Resources/usr/opt/freetype/lib
>> /private/tmp/[email protected]/octave-6.0.90/liboctave/.libs/liboctave.dylib
>> liboctave/.libs/liboctave.dylib -framework QtNetwork -framework
>> QtPrintSupport -framework QtHelp -framework QtWidgets -framework QtGui
>> -framework QtSql -framework QtXml -framework QtCore -lqscintilla2_qt5
>> -framework QtOpenGL -lhdf5
>> /Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/graphicsmagick/1.3.35/lib/libGraphicsMagick++.dylib
>> /Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/graphicsmagick/1.3.35/lib/libGraphicsMagick.dylib
>> -llcms2 -lbz2 -lltdl -lpthread -lz -framework OpenGL -lfontconfig
>> -lfreetype -framework Carbon -lgl2ps -lcurl -lcholmod -lumfpack -lamd
>> -lcamd -lcolamd -lccolamd -lcxsparse -lsuitesparseconfig
>> /Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/arpack/3.7.0_5/libexec/lib/libarpack.dylib
>> -lqrupdate -lfftw3_threads -lfftw3 -lfftw3f_threads -lfftw3f -lopenblas
>> -lreadline -lncurses -lpcre -ldl -lgfortran -lquadmath -liconv -lm
>> -pthread
>> -F/Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/qt-octave-app/5.15.1/lib
>> -F/Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/qt-octave-app/5.15.1/lib
>> -F/Applications/Octave-6.0.90.app/Contents/Resources/usr/opt/qt-octave-app/lib
>> -Wl,-framework -Wl,CoreFoundation -Wl,-dylib_file
>> -Wl,/Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/[email protected]/6.0.90/lib/octave/6.0.90/liboctave.8.dylib:/private/tmp/[email protected]/octave-6.0.90/liboctave/.libs/liboctave.dylib
>> -pthread -framework OpenGL -framework Carbon -framework QtNetwork
>> -framework QtPrintSupport -framework QtHelp -framework QtWidgets
>> -framework QtGui -framework QtSql -framework QtXml -framework QtCore
>> -framework QtOpenGL -install_name
>> /Applications/Octave-6.0.90.app/Contents/Resources/usr/Cellar/[email protected]/6.0.90/lib/octave/6.0.90/liboctgui.6.dylib
>> -compatibility_version 7 -current_version 7.0 -Wl,-single_module
>> Undefined symbols for architecture x86_64:
>>    "_class_getClassMethod", referenced from:
>>        octave::base_qobject::base_qobject(octave::qt_application&) in
>> libgui-src.a(libgui_src_la-octave-qobject.o)
>>    "_class_getInstanceMethod", referenced from:
>>        octave::base_qobject::base_qobject(octave::qt_application&) in
>> libgui-src.a(libgui_src_la-octave-qobject.o)
>>    "_objc_getClass", referenced from:
>>        octave::base_qobject::base_qobject(octave::qt_application&) in
>> libgui-src.a(libgui_src_la-octave-qobject.o)
>>    "_objc_msgSend", referenced from:
>>        octave::base_qobject::base_qobject(octave::qt_application&) in
>> libgui-src.a(libgui_src_la-octave-qobject.o)
>>    "_sel_getUid", referenced from:
>>        octave::base_qobject::base_qobject(octave::qt_application&) in
>> libgui-src.a(libgui_src_la-octave-qobject.o)
>> ld: symbol(s) not found for architecture x86_64
>> clang: error: linker command failed with exit code 1 (use -v to see
>> invocation)
>> make[2]: *** [libgui/liboctgui.la] Error 1
>> make[1]: *** [all-recursive] Error 1
>> make: *** [all] Error 2
>>
>>
>> Anyone know what might be going on there?
>>
>> Build went fine against Qt 5.12 on macOS 10.14. I'm trying other
>> combinations of OS and Qt version to try to narrow the issue down, but
>> these builds do take a while...
>>
>> Cheers,
>> Andrew
>>
> 
> Not sure what is causing this and how this can relate to the Qt version.
> But the error seems to come from some MacOS specific code:
> https://hg.savannah.gnu.org/hgweb/octave/file/9cd608134ec5/libgui/src/octave-qobject.cc#l81
> 
> "class_getClassMethod" and the other functions are from a Mac API.
> E.g.: https://developer.apple.com/documentation/objectivec/1418887-class_getclassmethod
> 
> I don't know how calling those Objective C functions from C++ is supposed to work. But IIUC, the same code worked correctly in the past...
> 
> Maybe a missing system library in the linker flags?
> 
> Markus

Oh yeahhhh... I think I actually wrote that code.

Okay, now I know where to look. I'll try to hunt this down. Thanks!

Cheers,
Andrew