ld: symbol(s) not found for architecture x86_64 qt - c++

Question

I'm trying to compile a basic Qt program:
#include <iostream>
#include <QApplication>
int main(int argc, char** argv) {
QApplication app(argc, argv);
std::cout << "test" << std::endl;
}
To start a Qt-project I did the following:
Make a project.pro file:
TEMPLATE += app
QT += widgets gui
SOURCES += main.cpp
Run the qmake command.
Edit the following in the generated Makefile:
-mmacosx-version-min=10.15.3 in CXXFLAGS
remove the -c argument from the compiler
Than I ran make and got the following error output:
/Library/Developer/CommandLineTools/usr/bin/clang++ -pipe -stdlib=libc++ -O2 -std=gnu++11 -arch x86_64 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mmacosx-version-min=10.15.3 -Wall -Wextra -fPIC -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I. -I/usr/local/Cellar/qt/5.14.1/lib/QtWidgets.framework/Headers -I/usr/local/Cellar/qt/5.14.1/lib/QtGui.framework/Headers -I/usr/local/Cellar/qt/5.14.1/lib/QtCore.framework/Headers -I. -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/OpenGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/AGL.framework/Headers -I/usr/local/Cellar/qt/5.14.1/mkspecs/macx-clang -F/usr/local/Cellar/qt/5.14.1/lib -o main.o main.cpp
Undefined symbols for architecture x86_64:
"QApplication::QApplication(int&, char**, int)", referenced from:
_main in main-96fd09.o
"QApplication::~QApplication()", referenced from:
_main in main-96fd09.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: *** [main.o] Error 1
I might have an idea what is causing this, when running make -v I get this output:
This program built for i386-apple-darwin11.3.0
clang++ --version generates this output:
Apple clang version 11.0.0 (clang-1100.0.33.16)
Target: x86_64-apple-darwin19.3.0
Thread model: posix
I think the Makefile is trying to compile my code for an older architecture and that's generating a conflict but I'm not sure. My system is a Macbook Pro running MacOS Catalina 10.15.3. Qt is version 15.4.1. Qmake is version 3.1.
Full Makefile:
#############################################################################
# Makefile for building: test.app/Contents/MacOS/test
# Generated by qmake (3.1) (Qt 5.14.1)
# Project: test.pro
# Template: app
# Command: /usr/local/Cellar/qt/5.14.1/bin/qmake -o Makefile test.pro
#############################################################################
MAKEFILE = Makefile
EQ = =
####### Compiler, tools and options
CC = /Library/Developer/CommandLineTools/usr/bin/clang
CXX = /Library/Developer/CommandLineTools/usr/bin/clang++
DEFINES = -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB
CFLAGS = -pipe -O2 $(EXPORT_ARCH_ARGS) -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mmacosx-version-min=10.13 -Wall -Wextra -fPIC $(DEFINES)
CXXFLAGS = -pipe -stdlib=libc++ -O2 -std=gnu++11 $(EXPORT_ARCH_ARGS) -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mmacosx-version-min=10.15.3 -Wall -Wextra -fPIC $(DEFINES)
INCPATH = -I. -I/usr/local/Cellar/qt/5.14.1/lib/QtWidgets.framework/Headers -I/usr/local/Cellar/qt/5.14.1/lib/QtGui.framework/Headers -I/usr/local/Cellar/qt/5.14.1/lib/QtCore.framework/Headers -I. -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/OpenGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/AGL.framework/Headers -I/usr/local/Cellar/qt/5.14.1/mkspecs/macx-clang -F/usr/local/Cellar/qt/5.14.1/lib
QMAKE = /usr/local/Cellar/qt/5.14.1/bin/qmake
DEL_FILE = rm -f
CHK_DIR_EXISTS= test -d
MKDIR = mkdir -p
COPY = cp -f
COPY_FILE = cp -f
COPY_DIR = cp -f -R
INSTALL_FILE = install -m 644 -p
INSTALL_PROGRAM = install -m 755 -p
INSTALL_DIR = cp -f -R
QINSTALL = /usr/local/Cellar/qt/5.14.1/bin/qmake -install qinstall
QINSTALL_PROGRAM = /usr/local/Cellar/qt/5.14.1/bin/qmake -install qinstall -exe
DEL_FILE = rm -f
SYMLINK = ln -f -s
DEL_DIR = rmdir
MOVE = mv -f
TAR = tar -cf
COMPRESS = gzip -9f
DISTNAME = test1.0.0
DISTDIR = /Users/myName/School/C++/QtTest/.tmp/test1.0.0
LINK = /Library/Developer/CommandLineTools/usr/bin/clang++
LFLAGS = -stdlib=libc++ -headerpad_max_install_names $(EXPORT_ARCH_ARGS) -Wl,-syslibroot,/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mmacosx-version-min=10.13 -Wl,-rpath,#executable_path/../Frameworks
LIBS = $(SUBLIBS) -F/usr/local/Cellar/qt/5.14.1/lib -framework QtWidgets -framework QtGui -framework AppKit -framework Metal -framework QtCore -framework DiskArbitration -framework IOKit -framework OpenGL -framework AGL
AR = /Library/Developer/CommandLineTools/usr/bin/ar cq
RANLIB = /Library/Developer/CommandLineTools/usr/bin/ranlib -s
SED = sed
STRIP = strip
####### Output directory
OBJECTS_DIR = ./
####### Files
SOURCES = main.cpp
OBJECTS = main.o
DIST = /usr/local/Cellar/qt/5.14.1/mkspecs/features/spec_pre.prf \
/usr/local/Cellar/qt/5.14.1/mkspecs/qdevice.pri \
/usr/local/Cellar/qt/5.14.1/mkspecs/features/device_config.prf \
/usr/local/Cellar/qt/5.14.1/mkspecs/common/unix.conf \
/usr/local/Cellar/qt/5.14.1/mkspecs/common/mac.conf \
/usr/local/Cellar/qt/5.14.1/mkspecs/features/mac/rez.prf \
/usr/local/Cellar/qt/5.14.1/mkspecs/features/mac/asset_catalogs.prf \
/usr/local/Cellar/qt/5.14.1/mkspecs/features/testcase_targets.prf \
/usr/local/Cellar/qt/5.14.1/mkspecs/features/exceptions.prf \
/usr/local/Cellar/qt/5.14.1/mkspecs/features/yacc.prf \
/usr/local/Cellar/qt/5.14.1/mkspecs/features/lex.prf \
MORE FILES HERE
test.pro main.cpp
QMAKE_TARGET = test
DESTDIR =
TARGET = test.app/Contents/MacOS/test
####### Custom Variables
EXPORT_QMAKE_MAC_SDK = macosx
EXPORT_QMAKE_MAC_SDK_VERSION = 10.15.1
EXPORT_QMAKE_XCODE_DEVELOPER_PATH = /Library/Developer/CommandLineTools
EXPORT_VALID_ARCHS = x86_64
EXPORT_ACTIVE_ARCHS = $(filter $(EXPORT_VALID_ARCHS), $(ARCHS))
EXPORT_ARCH_ARGS = $(foreach arch, $(if $(EXPORT_ACTIVE_ARCHS), $(EXPORT_ACTIVE_ARCHS), $(EXPORT_VALID_ARCHS)), -arch $(arch))
EXPORT__PRO_FILE_ = /Users/myName/School/C++/QtTest/test.pro
include /usr/local/Cellar/qt/5.14.1/mkspecs/features/mac/sdk.mk
first: all
####### Build rules
test.app/Contents/MacOS/test: $(OBJECTS)
#test -d test.app/Contents/MacOS/ || mkdir -p test.app/Contents/MacOS/
$(LINK) $(LFLAGS) -o $(TARGET) $(OBJECTS) $(OBJCOMP) $(LIBS)
Makefile: test.pro /usr/local/Cellar/qt/5.14.1/mkspecs/macx-clang/qmake.conf /usr/local/Cellar/qt/5.14.1/mkspecs/features/spec_pre.prf \
/usr/local/Cellar/qt/5.14.1/mkspecs/qdevice.pri \
/usr/local/Cellar/qt/5.14.1/mkspecs/features/device_config.prf \
/usr/local/Cellar/qt/5.14.1/mkspecs/common/unix.conf \
/usr/local/Cellar/qt/5.14.1/mkspecs/features/exceptions.prf \
/usr/local/Cellar/qt/5.14.1/mkspecs/features/yacc.prf \
/usr/local/Cellar/qt/5.14.1/mkspecs/features/lex.prf \
test.pro \
/usr/local/Cellar/qt/5.14.1/lib/QtWidgets.framework/Resources/QtWidgets.prl \
/usr/local/Cellar/qt/5.14.1/lib/QtGui.framework/Resources/QtGui.prl \
/usr/local/Cellar/qt/5.14.1/lib/QtCore.framework/Resources/QtCore.prl
MORE FILES HERE
$(QMAKE) -o Makefile test.pro
/usr/local/Cellar/qt/5.14.1/mkspecs/features/spec_pre.prf:
/usr/local/Cellar/qt/5.14.1/mkspecs/qdevice.pri:
/usr/local/Cellar/qt/5.14.1/mkspecs/features/device_config.prf:
/usr/local/Cellar/qt/5.14.1/mkspecs/common/unix.conf:
/usr/local/Cellar/qt/5.14.1/mkspecs/common/mac.conf:
/usr/local/Cellar/qt/5.14.1/mkspecs/features/lex.prf:
test.pro:
/usr/local/Cellar/qt/5.14.1/lib/QtWidgets.framework/Resources/QtWidgets.prl:
/usr/local/Cellar/qt/5.14.1/lib/QtGui.framework/Resources/QtGui.prl:
/usr/local/Cellar/qt/5.14.1/lib/QtCore.framework/Resources/QtCore.prl:
MORE FILES HERE
qmake: FORCE
#$(QMAKE) -o Makefile test.pro
qmake_all: FORCE
test.app/Contents/PkgInfo:
#test -d test.app/Contents || mkdir -p test.app/Contents
#$(DEL_FILE) test.app/Contents/PkgInfo
#echo "APPL????" > test.app/Contents/PkgInfo
test.app/Contents/Resources/empty.lproj:
#test -d test.app/Contents/Resources || mkdir -p test.app/Contents/Resources
#touch test.app/Contents/Resources/empty.lproj
test.app/Contents/Info.plist:
#test -d test.app/Contents || mkdir -p test.app/Contents
#$(DEL_FILE) test.app/Contents/Info.plist
#sed -e "s,#SHORT_VERSION#,1.0,g" -e "s,\$${QMAKE_SHORT_VERSION},1.0,g" -e "s,#FULL_VERSION#,1.0.0,g" -e "s,\$${QMAKE_FULL_VERSION},1.0.0,g" -e "s,#TYPEINFO#,????,g" -e "s,\$${QMAKE_PKGINFO_TYPEINFO},????,g" -e "s,#BUNDLEIDENTIFIER#,com.yourcompany.test,g" -e "s,\$${PRODUCT_BUNDLE_IDENTIFIER},com.yourcompany.test,g" -e "s,\$${MACOSX_DEPLOYMENT_TARGET},10.13,g" -e "s,\$${IPHONEOS_DEPLOYMENT_TARGET},,g" -e "s,\$${TVOS_DEPLOYMENT_TARGET},,g" -e "s,\$${WATCHOS_DEPLOYMENT_TARGET},,g" -e "s,#ICON#,,g" -e "s,\$${ASSETCATALOG_COMPILER_APPICON_NAME},,g" -e "s,#EXECUTABLE#,test,g" -e "s,#LIBRARY#,test,g" -e "s,\$${EXECUTABLE_NAME},test,g" -e "s,#TYPEINFO#,????,g" -e "s,\$${QMAKE_PKGINFO_TYPEINFO},????,g" /usr/local/Cellar/qt/5.14.1/mkspecs/macx-clang/Info.plist.app >test.app/Contents/Info.plist
all: Makefile \
test.app/Contents/PkgInfo \
test.app/Contents/Resources/empty.lproj \
test.app/Contents/Info.plist test.app/Contents/MacOS/test
dist: distdir FORCE
(cd `dirname $(DISTDIR)` && $(TAR) $(DISTNAME).tar $(DISTNAME) && $(COMPRESS) $(DISTNAME).tar) && $(MOVE) `dirname $(DISTDIR)`/$(DISTNAME).tar.gz . && $(DEL_FILE) -r $(DISTDIR)
distdir: FORCE
#test -d $(DISTDIR) || mkdir -p $(DISTDIR)
$(COPY_FILE) --parents $(DIST) $(DISTDIR)/
$(COPY_FILE) --parents /usr/local/Cellar/qt/5.14.1/mkspecs/features/data/dummy.cpp $(DISTDIR)/
$(COPY_FILE) --parents main.cpp $(DISTDIR)/
clean: compiler_clean
-$(DEL_FILE) $(OBJECTS)
-$(DEL_FILE) *~ core *.core
distclean: clean
-$(DEL_FILE) -r test.app
-$(DEL_FILE) .qmake.stash
-$(DEL_FILE) Makefile
####### Sub-libraries
xcodeproj:
#$(QMAKE) -spec macx-xcode "$(EXPORT__PRO_FILE_)"
mocclean: compiler_moc_header_clean compiler_moc_objc_header_clean compiler_moc_source_clean
mocables: compiler_moc_header_make_all compiler_moc_objc_header_make_all compiler_moc_source_make_all
check: first
benchmark: first
compiler_rcc_make_all:
compiler_rcc_clean:
compiler_moc_predefs_make_all: moc_predefs.h
compiler_moc_predefs_clean:
-$(DEL_FILE) moc_predefs.h
moc_predefs.h: /usr/local/Cellar/qt/5.14.1/mkspecs/features/data/dummy.cpp
/Library/Developer/CommandLineTools/usr/bin/clang++ -pipe -stdlib=libc++ -O2 -std=gnu++11 $(EXPORT_ARCH_ARGS) -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mmacosx-version-min=10.13 -Wall -Wextra -dM -E -o moc_predefs.h /usr/local/Cellar/qt/5.14.1/mkspecs/features/data/dummy.cpp
compiler_moc_header_make_all:
compiler_moc_header_clean:
compiler_moc_objc_header_make_all:
compiler_moc_objc_header_clean:
compiler_moc_source_make_all:
compiler_moc_source_clean:
compiler_uic_make_all:
compiler_uic_clean:
compiler_rez_source_make_all:
compiler_rez_source_clean:
compiler_yacc_decl_make_all:
compiler_yacc_decl_clean:
compiler_yacc_impl_make_all:
compiler_yacc_impl_clean:
compiler_lex_make_all:
compiler_lex_clean:
compiler_clean: compiler_moc_predefs_clean
####### Compile
main.o: main.cpp /usr/local/Cellar/qt/5.14.1/lib/QtWidgets.framework/Headers/QApplication \
/usr/local/Cellar/qt/5.14.1/lib/QtWidgets.framework/Headers/qapplication.h
$(CXX) $(CXXFLAGS) $(INCPATH) -o main.o main.cpp
####### Install
install: FORCE
uninstall: FORCE
FORCE:
Thanks!

Answer 1

I made a very basic mistake. Everything was working, but the Makefile outputted a main.o file. I tried to execute my application by using ./main.o. This is not possible.
The correct way to execute a Qt application is by using open main.app.
No need to alter the makefile.
Create a myApp.pro file
Example:
TEMPLATE += app
QT += widgets gui
SOURCES += myApp.cpp
Execute qmake
Execute make
Execute open myApp.app