Failing to target ios simulator with CMAKE - getting No known features for CXX compiler error

[qtusr]

Hi,

My context: macOS 12.6 (21G115), Monterey, Qt 6.4.0 LGPL 3.0, I installed it last night, Qt Creator 8.0.1.
What do I want to do: create a widgets project with Qt Creator and run it on the IOS simulator.
When I created the test project I selected CMAKE and I selected the Qt 6.4.0 for iOS, Qt 6.4.0 for iOS Simulator and Qt 6.4.0 for macOS kits.

When I tried to compile this project I got:

Running /Users/qtusr/Qt/Tools/CMake/CMake.app/Contents/bin/cmake -S /Users/qtusr/Documents/development/Qt/TestIos3 -B /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS -DCMAKE_GENERATOR:STRING=Xcode '-DCMAKE_PROJECT_INCLUDE_BEFORE:FILEPATH=/Users/qtusr/Qt/Qt Creator.app/Contents/Resources/package-manager/auto-setup.cmake' -DQT_QMAKE_EXECUTABLE:FILEPATH=/Users/qtusr/Qt/6.4.0/ios/bin/qmake -DCMAKE_PREFIX_PATH:PATH=/Users/qtusr/Qt/6.4.0/ios -DCMAKE_C_COMPILER:FILEPATH=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -DCMAKE_CXX_COMPILER:FILEPATH=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -DCMAKE_TOOLCHAIN_FILE:FILEPATH=/Users/qtusr/Qt/6.4.0/ios/lib/cmake/Qt6/qt.toolchain.cmake -DCMAKE_OSX_ARCHITECTURES:STRING=arm64 -DCMAKE_OSX_SYSROOT:STRING=iphoneos -DCMAKE_CXX_FLAGS_INIT:STRING=-DQT_QML_DEBUG -DCMAKE_XCODE_ATTRIBUTE_DEVELOPMENT_TEAM:STRING=M8R6XHV5V6 in /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS.
Running /Users/qtusr/Qt/Tools/CMake/CMake.app/Contents/bin/cmake -S /Users/qtusr/Documents/development/Qt/TestIos3 -B /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator -DCMAKE_GENERATOR:STRING=Xcode '-DCMAKE_PROJECT_INCLUDE_BEFORE:FILEPATH=/Users/qtusr/Qt/Qt Creator.app/Contents/Resources/package-manager/auto-setup.cmake' -DQT_QMAKE_EXECUTABLE:FILEPATH=/Users/qtusr/Qt/6.4.0/ios/bin/qmake -DCMAKE_PREFIX_PATH:PATH=/Users/qtusr/Qt/6.4.0/ios -DCMAKE_C_COMPILER:FILEPATH=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -DCMAKE_CXX_COMPILER:FILEPATH=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -DCMAKE_TOOLCHAIN_FILE:FILEPATH=/Users/qtusr/Qt/6.4.0/ios/lib/cmake/Qt6/qt.toolchain.cmake -DCMAKE_OSX_ARCHITECTURES:STRING=x86_64 -DCMAKE_OSX_SYSROOT:STRING=iphonesimulator -DCMAKE_CXX_FLAGS_INIT:STRING=-DQT_QML_DEBUG in /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator.
-- The CXX compiler identification is unknown
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ - skipped
-- Looking for C++ include pthread.h
-- Looking for C++ include pthread.h - found
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE  
-- Found ZLIB: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator16.0.sdk/usr/lib/libz.tbd (found version "1.2.11") 
-- Found WrapSystemZLIB: TRUE  
-- Using system ZLIB.
-- Found WrapZLIB: TRUE  
-- Performing Test HAVE_STDATOMIC
-- Performing Test HAVE_STDATOMIC - Success
-- Found WrapAtomic: TRUE  
-- Looking for backtrace
-- Looking for backtrace - found
-- backtrace facility detected in default set of libraries
-- Found Backtrace: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator16.0.sdk/usr/include  
-- Using Qt bundled PCRE2.
-- Found WrapPCRE2: TRUE  
-- Performing Test HAVE_GETTIME
-- Performing Test HAVE_GETTIME - Success
-- Found WrapRt: TRUE  
-- Performing Test HAVE_EGL
-- Performing Test HAVE_EGL - Failed
-- Could NOT find EGL (missing: EGL_INCLUDE_DIR HAVE_EGL EGL_LIBRARY) 
-- Performing Test HAVE_GLESv2
-- Performing Test HAVE_GLESv2 - Success
-- Found GLESv2: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator16.0.sdk/System/Library/Frameworks/OpenGLES.framework  
-- Using Qt bundled PNG.
-- Found WrapPNG: TRUE  
-- Using Qt bundled Harfbuzz.
-- Found WrapHarfbuzz: TRUE  
-- Using Qt bundled Freetype.
-- Found WrapFreetype: TRUE  
-- Using Qt bundled Jpeg.
-- Found WrapJpeg: TRUE  
-- Found AVFoundation: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator16.0.sdk/System/Library/Frameworks/AVFoundation.framework  
-- Configuring done
CMake Error in CMakeLists.txt:
  No known features for CXX compiler

  ""

  version .


CMake Generate step failed.  Build files cannot be regenerated correctly.
CMake process exited with exit code 1.

Elapsed time: 00:27.

This is from the error file:

    cd /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp
    /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -x c++ -target x86_64-apple-ios13.0-simulator -fmessage-length\=0 -fdiagnostics-show-note-include-stack -fmacro-backtrace-limit\=0 -Wno-trigraphs -fpascal-strings -O0 -Wno-missing-field-initializers -Wno-missing-prototypes -Wno-return-type -Wno-non-virtual-dtor -Wno-overloaded-virtual -Wno-exit-time-destructors -Wno-missing-braces -Wparentheses -Wswitch -Wno-unused-function -Wno-unused-label -Wno-unused-parameter -Wno-unused-variable -Wunused-value -Wno-empty-body -Wno-uninitialized -Wno-unknown-pragmas -Wno-shadow -Wno-four-char-constants -Wno-conversion -Wno-constant-conversion -Wno-int-conversion -Wno-bool-conversion -Wno-enum-conversion -Wno-float-conversion -Wno-non-literal-null-conversion -Wno-objc-literal-conversion -Wshorten-64-to-32 -Wno-newline-eof -Wno-c++11-extensions -Wno-implicit-fallthrough -DCMAKE_INTDIR\=\"Debug-iphonesimulator\" -DHAVE_EGL -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator16.0.sdk -fasm-blocks -fstrict-aliasing -Wdeprecated-declarations -Winvalid-offsetof -Wno-sign-conversion -Wno-infinite-recursion -Wno-move -Wno-comma -Wno-block-capture-autoreleasing -Wno-strict-prototypes -Wno-range-loop-analysis -Wno-semicolon-before-method-body -I/Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/Debug/include -I/Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/CMAKE_TRY_COMPILE.build/Debug-iphonesimulator/cmTC_704b0.build/DerivedSources-normal/x86_64 -I/Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/CMAKE_TRY_COMPILE.build/Debug-iphonesimulator/cmTC_704b0.build/DerivedSources/x86_64 -I/Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/CMAKE_TRY_COMPILE.build/Debug-iphonesimulator/cmTC_704b0.build/DerivedSources -F/Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/Debug -DQT_QML_DEBUG -MMD -MT dependencies -MF /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/CMAKE_TRY_COMPILE.build/Debug-iphonesimulator/cmTC_704b0.build/Objects-normal/x86_64/src.d --serialize-diagnostics /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/CMAKE_TRY_COMPILE.build/Debug-iphonesimulator/cmTC_704b0.build/Objects-normal/x86_64/src.dia -c /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/src.cxx -o /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/CMAKE_TRY_COMPILE.build/Debug-iphonesimulator/cmTC_704b0.build/Objects-normal/x86_64/src.o
/Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/src.cxx:2:10: fatal error: 'EGL/egl.h' file not found
#include <EGL/egl.h>
         ^~~~~~~~~~~
1 error generated.

WriteAuxiliaryFile /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/CMAKE_TRY_COMPILE.build/Debug-iphonesimulator/cmTC_704b0.build/Objects-normal/x86_64/cmTC_704b0.LinkFileList (in target 'cmTC_704b0' from project 'CMAKE_TRY_COMPILE')
    cd /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp
    write-file /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/CMAKE_TRY_COMPILE.build/Debug-iphonesimulator/cmTC_704b0.build/Objects-normal/x86_64/cmTC_704b0.LinkFileList

** BUILD FAILED **


The following build commands failed:
	CompileC /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/CMAKE_TRY_COMPILE.build/Debug-iphonesimulator/cmTC_704b0.build/Objects-normal/x86_64/src.o /Users/qtusr/Documents/development/Qt/build-TestIos3-Qt_6_4_0_for_iOS_Simulator/CMakeFiles/CMakeTmp/src.cxx normal x86_64 c++ com.apple.compilers.llvm.clang.1_0.compiler (in target 'cmTC_704b0' from project 'CMAKE_TRY_COMPILE')
(1 failure)


Source file was:

#include <EGL/egl.h>

int main(int, char **) {
    EGLint x = 0; EGLDisplay dpy = 0; EGLContext ctx = 0;
    eglDestroyContext(dpy, ctx);
}

CMakeLists.txt:

cmake_minimum_required(VERSION 3.5)

project(TestIos3 VERSION 0.1 LANGUAGES CXX)

set(CMAKE_INCLUDE_CURRENT_DIR ON)

set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

find_package(QT NAMES Qt6 Qt5 REQUIRED COMPONENTS Widgets)
find_package(Qt${QT_VERSION_MAJOR} REQUIRED COMPONENTS Widgets)

set(PROJECT_SOURCES
        main.cpp
        mainwindow.cpp
        mainwindow.h
        mainwindow.ui
)

if(${QT_VERSION_MAJOR} GREATER_EQUAL 6)
    qt_add_executable(TestIos3
        MANUAL_FINALIZATION
        ${PROJECT_SOURCES}
    )
# Define target properties for Android with Qt 6 as:
#    set_property(TARGET TestIos3 APPEND PROPERTY QT_ANDROID_PACKAGE_SOURCE_DIR
#                 ${CMAKE_CURRENT_SOURCE_DIR}/android)
# For more information, see https://doc.qt.io/qt-6/qt-add-executable.html#target-creation
else()
    if(ANDROID)
        add_library(TestIos3 SHARED
            ${PROJECT_SOURCES}
        )
# Define properties for Android with Qt 5 after find_package() calls as:
#    set(ANDROID_PACKAGE_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/android")
    else()
        add_executable(TestIos3
            ${PROJECT_SOURCES}
        )
    endif()
endif()

target_link_libraries(TestIos3 PRIVATE Qt${QT_VERSION_MAJOR}::Widgets)

set_target_properties(TestIos3 PROPERTIES
    MACOSX_BUNDLE_GUI_IDENTIFIER my.example.com
    MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION}
    MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
    MACOSX_BUNDLE TRUE
    WIN32_EXECUTABLE TRUE
)

install(TARGETS TestIos3
    BUNDLE DESTINATION .
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})

if(QT_VERSION_MAJOR EQUAL 6)
    qt_finalize_executable(TestIos3)
endif()

Right off the bat I should say that when I created the same type of project but I selected qmake, the whole thing worked fine and I was able to run the app in the simulator. The project also works with CMAKE when I targeted MacOS.

I know that Qt adopted CMAKE - I've seen this video where he justified why they chose CMAKE. He convinced me, and I chose CMAKE as well, and I started to even learn more about it.

I tried to find more information about this error but none of the suggestions I found worked. Here is on post on SO, but I don't understand the answer. I tried different required versions of CMAKE but none of them worked.

Any idea about what's going on? What can I do to get it working? Imo, this is a basic starting point, app created with Qt Creator, uses CMAKE, targets iOS simulator, and I cannot get past the compilation phase.

Update: I submitted a bug report: https://bugreports.qt.io/browse/QTBUG-107695 .

Thank you!

[qtusr]

The solution was to install cmake 3.24.2. This fixes the compilation process.