Question

我已经从源代码构建了OpenCV v4.2，并将其安装到/usr/local。 OPENCVConfig.cmake文件位于/usr/local/lib/cmake/opencv4目录中：

paul@paul-desktop:/usr/local/lib/cmake/opencv4$ dir
OpenCVConfig.cmake  OpenCVConfig-version.cmake  OpenCVModules.cmake  OpenCVModules-release.cmake

这是我的CMakeLists.txt文件，它拼命试图满足find_package：

cmake_minimum_required(VERSION 3.16.2)
project(af VERSION 0.1.0 LANGUAGES CXX)

set(CPACK_PROJECT_NAME ${PROJECT_NAME})
set(CPACK_PROJECT_VERSION ${PROJECT_VERSION})
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_BUILD_PARALLEL_LEVEL 4)
set(CMAKE_PREFIX_PATH /usr/local/lib/cmake/opencv4)
set(ENV{OPENCV_DIR} /usr/local/lib/cmake/opencv4)
set(OPENCV_DIR /usr/local/lib/cmake/opencv4)

find_package(OPENCV REQUIRED)

add_executable(af main.cpp)

会产生此错误：

[build] CMake Error at CMakeLists.txt:12 (find_package):
[build]   By not providing "FindOPENCV.cmake" in CMAKE_MODULE_PATH this project has
[build]   asked CMake to find a package configuration file provided by "OPENCV", but
[build]   CMake did not find one.
[build] 
[build]   Could not find a package configuration file provided by "OPENCV" with any
[build]   of the following names:
[build] 
[build]     OPENCVConfig.cmake
[build]     opencv-config.cmake
[build] 
[build]   Add the installation prefix of "OPENCV" to CMAKE_PREFIX_PATH or set
[build]   "OPENCV_DIR" to a directory containing one of the above files.  If "OPENCV"
[build]   provides a separate development package or SDK, be sure it has been
[build]   installed.

当我用CMakeCache.txt打开cmake-gui并将OPENCV_DIR手动设置为/usr/local/lib/cmake/opencv4时，我遇到了同样的错误，OPENCV_DIR变成了 OPENCV_DIR-NOTFOUND。

这是怎么回事？在我看来，我已经满足了错误消息中列出的要求，并且在解决类似问题时可以找到任何好的建议。

我不确定这是否重要，但是/usr/share/OpenCV/OpenCVConfig.cmake属于OpenCV的其他版本。

Answer 1

包名称区分大小写。在find_package中使用的OpenCV软件包的专有名称是OpenCV，而不是OPENCV。

实际上，CMake中唯一不区分大小写的东西是宏/函数名。 其他所有都是区分大小写的。

某些变量和文件使用名称的大写或小写转换。例如。 OPENCV_DIR变量在大写中使用包名，而opencv-config.cmake文件在小写中使用包名。但这并不否认区分大小写的方面。

cmake找不到“ OPENCV”提供的程序包配置文件

1 个答案: