CMAKE_PREFIX_PATH hilft CMake nicht bei der Suche nach QT5

Question

Von hier aus: https://stackoverflow.com/a/28327499/462608

Ich versuchte dies:

cmake_minimum_required(VERSION 2.8.12) 

project(qtquick_hello_cmake) 

set(CMAKE_PREFIX_PATH "/opt/Qt5.9.1/5.9.1/") 

set(CMAKE_INCLUDE_CURRENT_DIR ON) 
set(CMAKE_AUTOMOC ON) 
set(CMAKE_AUTORCC ON) 

find_package(Qt5 COMPONENTS Quick Core REQUIRED) 

qt5_add_resources(RESOURCES qml.qrc) 

add_executable(${PROJECT_NAME} "main.cpp" "qml.qrc") 

qt5_use_modules(${PROJECT_NAME} Quick Core) 

target_link_libraries(${PROJECT_NAME} Qt5::Core Qt5::Quick) 

Hier ist die Ausgabe von cmake .

:~/junk/qtquick_hello_cmake$ cmake . 
CMake Error at CMakeLists.txt:11 (find_package): 
    By not providing "FindQt5.cmake" in CMAKE_MODULE_PATH this project has 
    asked CMake to find a package configuration file provided by "Qt5", but 
    CMake did not find one. 

    Could not find a package configuration file provided by "Qt5" with any of 
    the following names: 

    Qt5Config.cmake 
    qt5-config.cmake 

    Add the installation prefix of "Qt5" to CMAKE_PREFIX_PATH or set "Qt5_DIR" 
    to a directory containing one of the above files. If "Qt5" provides a 
    separate development package or SDK, be sure it has been installed. 


-- Configuring incomplete, errors occurred! 
See also "/home/.../junk/qtquick_hello_cmake/CMakeFiles/CMakeOutput.log". 

ist zur ist zu zeigen, dass /opt/Qt5.9.1/ doe s existieren.

:~/junk/qtquick_hello_cmake$ cd /opt/Qt5.9.1/5.9.1/ 
:/opt/Qt5.9.1/5.9.1$ ls 
android_armv7 android_x86 gcc_64 Src 

Hier laufe ich die cmake mit -DCMAKE Option, aber der Ausgang ist immer noch gleich:

:~/junk/qtquick_hello_cmake$ cmake -DCMAKE_PREFIX_PATH=/opt/Qt5.9.1/5.9.1/ -DWITH_QT5=1 . 
CMake Error at CMakeLists.txt:11 (find_package): 
    By not providing "FindQt5.cmake" in CMAKE_MODULE_PATH this project has 
    asked CMake to find a package configuration file provided by "Qt5", but 
    CMake did not find one. 

    Could not find a package configuration file provided by "Qt5" with any of 
    the following names: 

    Qt5Config.cmake 
    qt5-config.cmake 

    Add the installation prefix of "Qt5" to CMAKE_PREFIX_PATH or set "Qt5_DIR" 
    to a directory containing one of the above files. If "Qt5" provides a 
    separate development package or SDK, be sure it has been installed. 


-- Configuring incomplete, errors occurred! 
See also "/home/.../junk/qtquick_hello_cmake/CMakeFiles/CMakeOutput.log". 

Inhalt des Verzeichnisses:

:~/junk/qtquick_hello_cmake$ ls 
CMakeCache.txt CMakeFiles CMakeLists.txt main.cpp main.qml qml.qrc 

Answer 1

I installiert die folgenden fehlenden Pakete:

sudo apt-get install qtbase5-dev 
sudo apt-get install qtdeclarative5-dev 

jede Art von Präfix Anbringen jetzt nicht erforderlich:

:~/junk/qtquick_hello_cmake$ cat CMakeLists.txt 
    cmake_minimum_required(VERSION 2.8.12) 

    project(qtquick_hello_cmake) 

    set(CMAKE_INCLUDE_CURRENT_DIR ON) 
    set(CMAKE_AUTOMOC ON) 
    set(CMAKE_AUTORCC ON) 

    find_package(Qt5 COMPONENTS Quick Core REQUIRED) 

    qt5_add_resources(RESOURCES qml.qrc) 

    add_executable(${PROJECT_NAME} "main.cpp" "qml.qrc") 

    qt5_use_modules(${PROJECT_NAME} Quick Core) 

    target_link_libraries(${PROJECT_NAME} Qt5::Core Qt5::Quick) 


:~/junk/qtquick_hello_cmake$ ls 
build CMakeLists.txt main.cpp main.qml qml.qrc 

:~/junk/qtquick_hello_cmake$ cd build/ 
:~/junk/qtquick_hello_cmake/build$ rm -rf * 

:~/junk/qtquick_hello_cmake/build$ cmake ../ 
-- The C compiler identification is GNU 4.8.4 
-- The CXX compiler identification is GNU 4.8.4 
-- Check for working C compiler: /usr/bin/cc 
-- Check for working C compiler: /usr/bin/cc -- works 
-- Detecting C compiler ABI info 
-- Detecting C compiler ABI info - done 
-- Check for working CXX compiler: /usr/bin/c++ 
-- Check for working CXX compiler: /usr/bin/c++ -- works 
-- Detecting CXX compiler ABI info 
-- Detecting CXX compiler ABI info - done 
-- Configuring done 
-- Generating done 
-- Build files have been written to: /home/.../junk/qtquick_hello_cmake/build 

Fehler sind nun weg.

Dank:
https://answers.ros.org/question/236324/could-not-find-a-package-configuration-file-provided-by-qt5widgets/
https://askubuntu.com/questions/508503/whats-the-development-package-for-qt5-in-14-04

Answer 2

CMake Fehlermeldung über find_package und Einstellung fehlgeschlagen CMAKE_PREFIX_PATH Variable

die Installation Präfix "QT5" Add

CMAKE_PREFIX_PATH

ist irgendwie irreführend. Es spricht nur über "Installationspräfix", aber diese Installation immer noch erfordert zu enthalten Qt5Config.cmake oder qt5-config.cmake Dateien im Inneren für die Auffindbarkeit von find_package.

Aber die Botschaft

Wenn „QT5“ bietet ein separates Entwicklungspaket oder SDK, sollten Sie es installiert wurde.

ist klar:

Eine Notwendigkeit, ein Entwicklungspaket zu installieren, die Dateien erforderliche Konfiguration enthält.

---

Alles oben ist nur anwendbar auf CONFIG Modus von find_package, wenn „Suchen“ Skript zur Verfügung gestellt wird weder durch CMake noch durch CMake Projekt, das diesen Befehl verwendet.