Qt 报错：Undefined symbols for architecture arm64

Bug：Undefined symbols for architecture arm64，完整的报错信息：

设备：MacBook Pro Apple M1

系统：macOS Ventura 13.0

Qt Creator：Qt Creator 9.0.0 Based on Qt 6.4.1 (Clang 13.0 (Apple), arm64)

Qt：Qt 6.4.0

Undefined symbols for architecture arm64:
  "Player::prepareCallLord()", referenced from:
      vtable for Player in moc_player.o
  "Player::preparePlayHand()", referenced from:
      vtable for Player in moc_player.o
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [Landlords.app/Contents/MacOS/Landlords] Error 1
23:00:12: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project Landlords (kit: Desktop (arm-darwin-generic-mach_o-64bit))
When executing step "Make"

尝试 1：有可能是因为 Qt 版本的原因，项目视频里面是用 5.15.2 的版本。

先试着链接 https://www.cnblogs.com/wqcwood/p/15138983.html 中的方法：

做到 make -j15 这一步的时候报错了；

尝试 2：使用 BrewHome 安装了 Qt 5.15.7，设置 Qt mkspec 路径 /opt/homebrew/opt/qt@5/mkspecs/linux-g++，编译的时候出现报错：

make: *** [scorepanel.o] Error 1
make: *** Waiting for unfinished jobs....
In file included from ../Landlords/userplayer.cpp:1:
In file included from ../Landlords/userplayer.h:4:
In file included from ../Landlords/player.h:4:
In file included from /opt/homebrew/Cellar/qt@5/5.15.7/lib/QtCore.framework/Headers/QObject:1:
/opt/homebrew/Cellar/qt@5/5.15.7/lib/QtCore.framework/Headers/qobject.h:46:10: fatal error: 'QtCore/qobjectdefs.h' file not found
#include 
         ^~~~~~~~~~~~~~~~~~~~~~
1 error generated.
1 error generated.
make: *** [cardpanel.o] Error 1
make: *** [main.o] Error 1
1 error generated.
make: *** [robot.o] Error 1
1 error generated.
make: *** [player.o] Error 1
1 error generated.
make: *** [userplayer.o] Error 1
1 error generated.
make: *** [gamecontrol.o] Error 1
11:46:07: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project Landlords (kit: Desktop (arm-darwin-generic-mach_o-64bit))
When executing step "Make"

尝试 3：询问了一下，认为应该是虚函数没有定义导致的

如果是基类声明了一个虚函数，但是没有为其定义函数体，那么就会出现这个错误；

因此有两个修改的方式：

• 第一个方法：就是将 Player.h 头文件中的虚函数写成纯虚函数 virtual void prepareCallLord() = 0;，只需要在后面令虚函数等于 0 就是纯虚函数；
• 第二个方法：在 Player.cpp 源文件中为虚函数定义一个空的函数体；

这样改完之后就能够编译成功了！