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社区首页 >问答首页 >如果安装了多个版本，cmake find_package(X [ version ])总是选择最高版本的X？

问如果安装了多个版本，cmake find_package(X [ version ])总是选择最高版本的X？
EN

Stack Overflow用户
提问于 2022-05-27 18:53:34
回答 1查看 214关注 0票数 1

我在运行cmake 3.23.0。我想要基于版本标准的find_library(VTK)。我的ubuntu20.04系统安装了两个版本的VTK：

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/usr/local/lib/cmake/vtk-8.2
/usr/local/lib/cmake/vtk-9.0

我的项目需要VTK版本8.x.x，即需要排除VTK 9.x.x -所以CMakeLists.txt包括：

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   find_package(VTK "8...<9" REQUIRED)

但是VTK_VERSION发现的是9.0.1 -考虑到约束，为什么呢？也试过

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find_package(VTK "8.0...<9.0" REQUIRED)
find_package(VTK "8.0.0...<9.0.0" REQUIRED)

同样的结果- VTK_VERSION 9.0.1被找到。在没有版本范围的情况下尝试，但是find_package()仍然返回VTK_VERSION 9.0.1：

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   find_package(VTK "8" REQUIRED) 
   find_package(VTK “8.2” REQUIRED)
   find_package(VTK “8.2.0” REQUIRED)

唯一真正返回VTK_VERSION 8.2.0的内容是：

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   find_package(VTK “8.2.0” REQUIRED EXACT)

这种行为是因为我的系统上安装了两个VTK版本，而find_packages()假设只安装了一个版本吗？

*更新#2: /usr/local/lib/cmake/vtk-中版本配置文件的内容。

/usr/local/lib/cmake/vtk-8.2/VTKConfigVersion.cmake：

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# This is a basic version file for the Config-mode of find_package().
# It is used by write_basic_package_version_file() as input file for configure_file()
# to create a version-file which can be installed along a config.cmake file.
#
# The created file sets PACKAGE_VERSION_EXACT if the current version string and
# the requested version string are exactly the same and it sets
# PACKAGE_VERSION_COMPATIBLE if the current version is >= requested version,
# but only if the requested major version is the same as the current one.
# The variable CVF_VERSION must be set before calling configure_file().


set(PACKAGE_VERSION "8.2.0")

if(PACKAGE_VERSION VERSION_LESS PACKAGE_FIND_VERSION)
  set(PACKAGE_VERSION_COMPATIBLE FALSE)
else()

  if("8.2.0" MATCHES "^([0-9]+)\\.")
    set(CVF_VERSION_MAJOR "${CMAKE_MATCH_1}")
  else()
    set(CVF_VERSION_MAJOR "8.2.0")
  endif()

  if(PACKAGE_FIND_VERSION_MAJOR STREQUAL CVF_VERSION_MAJOR)
    set(PACKAGE_VERSION_COMPATIBLE TRUE)
  else()
    set(PACKAGE_VERSION_COMPATIBLE FALSE)
  endif()

  if(PACKAGE_FIND_VERSION STREQUAL PACKAGE_VERSION)
      set(PACKAGE_VERSION_EXACT TRUE)
  endif()
endif()
# if the installed or the using project don't have CMAKE_SIZEOF_VOID_P set, ignore it:
if("${CMAKE_SIZEOF_VOID_P}" STREQUAL "" OR "8" STREQUAL "")
   return()
endif()

# check that the installed version has the same 32/64bit-ness as the one which is currently searching:
if(NOT CMAKE_SIZEOF_VOID_P STREQUAL "8")
  math(EXPR installedBits "8 * 8")
  set(PACKAGE_VERSION "${PACKAGE_VERSION} (${installedBits}bit)")
  set(PACKAGE_VERSION_UNSUITABLE TRUE)
endif()

/usr/local/lib/cmake/vtk-9.0/vtk-config-version.cmake：

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# This is a basic version file for the Config-mode of find_package().
# It is used by write_basic_package_version_file() as input file for configure_file()
# to create a version-file which can be installed along a config.cmake file.
#
# The created file sets PACKAGE_VERSION_EXACT if the current version string and
# the requested version string are exactly the same and it sets
# PACKAGE_VERSION_COMPATIBLE if the current version is >= requested version.
# The variable CVF_VERSION must be set before calling configure_file().

set(PACKAGE_VERSION "9.0.1")

if(PACKAGE_VERSION VERSION_LESS PACKAGE_FIND_VERSION)
  set(PACKAGE_VERSION_COMPATIBLE FALSE)
else()
  set(PACKAGE_VERSION_COMPATIBLE TRUE)
  if(PACKAGE_FIND_VERSION STREQUAL PACKAGE_VERSION)
    set(PACKAGE_VERSION_EXACT TRUE)
  endif()
endif()

# if the installed project requested no architecture check, don't perform the check
if("FALSE")
  return()
endif()

# if the installed or the using project don't have CMAKE_SIZEOF_VOID_P set, ignore it:
if("${CMAKE_SIZEOF_VOID_P}" STREQUAL "" OR "8" STREQUAL "")
   return()
endif()

# check that the installed version has the same 32/64bit-ness as the one which is currently searching:
if(NOT CMAKE_SIZEOF_VOID_P STREQUAL "8")
   math(EXPR installedBits "8 * 8")
   set(PACKAGE_VERSION "${PACKAGE_VERSION} (${installedBits}bit)")
   set(PACKAGE_VERSION_UNSUITABLE TRUE)
endif()

*更新#1:带有--调试-查找-pkg=VTK的CMake输出：

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CMake Debug Log at CMakeLists.txt:212 (find_package):
  find_package considered the following paths for VTK.cmake

    /home/oreilly/projects/mb-system/MB-System/build-utils/FindVTK.cmake
    /usr/local/share/cmake-3.23/Modules/FindVTK.cmake

  The file was not found.

  <PackageName>_ROOT CMake variable [CMAKE_FIND_USE_PACKAGE_ROOT_PATH].

    none

  CMAKE_PREFIX_PATH variable [CMAKE_FIND_USE_CMAKE_PATH].

    none

  CMAKE_FRAMEWORK_PATH and CMAKE_APPBUNDLE_PATH variables
  [CMAKE_FIND_USE_CMAKE_PATH].

    none

  Env variable VTK_DIR [CMAKE_FIND_USE_CMAKE_ENVIRONMENT_PATH].

    none

  CMAKE_PREFIX_PATH env variable [CMAKE_FIND_USE_CMAKE_ENVIRONMENT_PATH].

    none

  CMAKE_FRAMEWORK_PATH and CMAKE_APPBUNDLE_PATH env variables
  [CMAKE_FIND_USE_CMAKE_ENVIRONMENT_PATH].

  none

  Paths specified by the find_package HINTS option.

    none

  Standard system environment variables
  [CMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH].

    /home/oreilly/OpenSceneGraph/build
    /home/oreilly/projects/mb-system/MB-System/build
    /home/oreilly/projects/hotspot/onboard/smc-script
    /home/oreilly/projects/hotspot/onboard/script
    /home/oreilly/myUtilities
    /home/oreilly/cxxtest-4.3
    /home/oreilly/Qt/Tools/QtCreator
    /home/oreilly/Qt/5.14.2/gcc_64
    /home/oreilly/Android/Sdk/platform-tools
    /home/oreilly/android-studio/tools
    /home/oreilly/android-studio
    /home/oreilly/idea
    /home/oreilly
    /home/oreilly/.local
    /usr/local
    /usr
    /
    /usr/games
    /usr/local/games
    /snap
    /home/oreilly/anaconda2
CMake User Package Registry [CMAKE_FIND_USE_PACKAGE_REGISTRY].

    none

  CMake variables defined in the Platform file
  [CMAKE_FIND_USE_CMAKE_SYSTEM_PATH].

    /usr/X11R6
    /usr/pkg
    /opt

  

  CMake System Package Registry
  [CMAKE_FIND_PACKAGE_NO_SYSTEM_PACKAGE_REGISTRY].

    none

  Paths specified by the find_package PATHS option.

    none

  find_package considered the following locations for the Config module:

    /home/oreilly/OpenSceneGraph/build/VTKConfig.cmake
    /home/oreilly/OpenSceneGraph/build/vtk-config.cmake
    /home/oreilly/projects/mb-system/MB-System/build/VTKConfig.cmake
    /home/oreilly/projects/mb-system/MB-System/build/vtk-config.cmake
    /home/oreilly/projects/hotspot/onboard/smc-script/VTKConfig.cmake
    /home/oreilly/projects/hotspot/onboard/smc-script/vtk-config.cmake
    /home/oreilly/projects/hotspot/onboard/script/VTKConfig.cmake
 /home/oreilly/projects/hotspot/onboard/script/vtk-config.cmake
    /home/oreilly/myUtilities/VTKConfig.cmake
    /home/oreilly/myUtilities/vtk-config.cmake
    /home/oreilly/cxxtest-4.3/VTKConfig.cmake
    /home/oreilly/cxxtest-4.3/vtk-config.cmake
    /home/oreilly/Qt/Tools/QtCreator/VTKConfig.cmake
    /home/oreilly/Qt/Tools/QtCreator/vtk-config.cmake
    /home/oreilly/Qt/5.14.2/gcc_64/VTKConfig.cmake
    /home/oreilly/Qt/5.14.2/gcc_64/vtk-config.cmake
    /home/oreilly/Android/Sdk/platform-tools/VTKConfig.cmake
    /home/oreilly/Android/Sdk/platform-tools/vtk-config.cmake
    /home/oreilly/android-studio/tools/VTKConfig.cmake
    /home/oreilly/android-studio/tools/vtk-config.cmake
    /home/oreilly/android-studio/VTKConfig.cmake
    /home/oreilly/android-studio/vtk-config.cmake
    /home/oreilly/idea/VTKConfig.cmake
    /home/oreilly/idea/vtk-config.cmake
    /home/oreilly/VTKConfig.cmake
    /home/oreilly/vtk-config.cmake
    /home/oreilly/CMake/VTKConfig.cmake
    /home/oreilly/CMake/vtk-config.cmake
    /home/oreilly/vtk/VTKConfig.cmake
    /home/oreilly/vtk/vtk-config.cmake
    /home/oreilly/VTK-8.2.0/VTKConfig.cmake
    /home/oreilly/VTK-8.2.0/vtk-config.cmake
    /home/oreilly/VTKWikiExamples-master/VTKConfig.cmake
    /home/oreilly/VTKWikiExamples-master/vtk-config.cmake
    /home/oreilly/VTK-9.0.1/VTKConfig.cmake
    /home/oreilly/VTK-9.0.1/vtk-config.cmake
    /home/oreilly/VTKExamples/VTKConfig.cmake
    /home/oreilly/VTKExamples/vtk-config.cmake
    /home/oreilly/vtk/CMake/VTKConfig.cmake
    /home/oreilly/vtk/CMake/vtk-config.cmake
    /home/oreilly/VTK-8.2.0/CMake/VTKConfig.cmake
/home/oreilly/VTK-8.2.0/CMake/vtk-config.cmake
    /home/oreilly/VTKWikiExamples-master/CMake/VTKConfig.cmake
    /home/oreilly/VTKWikiExamples-master/CMake/vtk-config.cmake
    /home/oreilly/VTK-9.0.1/CMake/VTKConfig.cmake
    /home/oreilly/VTK-9.0.1/CMake/vtk-config.cmake
    /home/oreilly/VTKExamples/CMake/VTKConfig.cmake
    /home/oreilly/VTKExamples/CMake/vtk-config.cmake
    /home/oreilly/.local/VTKConfig.cmake
    /home/oreilly/.local/vtk-config.cmake
    /usr/local/VTKConfig.cmake
    /usr/local/vtk-config.cmake
    /usr/local/lib/cmake/vtk-9.0/VTKConfig.cmake
    /usr/local/lib/cmake/vtk-9.0/vtk-config.cmake

  The file was found at

    /usr/local/lib/cmake/vtk-9.0/vtk-config.cmake



CMake Debug Log at CMakeLists.txt:212 (find_package):


Found VTK package version 9.0.1, VTK_LIBRARIES: VTK::WrappingTools;VTK::ViewsQt;[et cetera...]
cmake
EN

回答 1

Stack Overflow用户

回答已采纳

发布于 2022-05-27 22:59:48

find_package根据搜索过程选择它找到的第一个包。当在搜索过程中断线时，它会按文件系统顺序排列。这取决于您的文件系统，因此没有指定。

对于版本选择，询问包的、*-config-version.cmake或*ConfigVersion.cmake脚本是否与请求的版本兼容。没有这样的脚本的包被认为是不兼容的。旧包通常不会理解版本范围，并且倾向于将像8.0.0...<9.0.0这样的表达式简单地看作是8.0.0。

您从--debug-find-pkg=VTK输出中看到的是，您的文件系统在VTK 8之前订购了VTK 9，这可能是因为它更新了，或者碰巧被分配给了一个较小的inode，或者谁知道呢？它不一定是字母顺序或其他什么的。

然后首先考虑VTK 9并加载vtk-9.0/vtk-config-version.cmake文件。如你所见：

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if(PACKAGE_VERSION VERSION_LESS PACKAGE_FIND_VERSION)
  set(PACKAGE_VERSION_COMPATIBLE FALSE)
else()
  set(PACKAGE_VERSION_COMPATIBLE TRUE)
  if(PACKAGE_FIND_VERSION STREQUAL PACKAGE_VERSION)
    set(PACKAGE_VERSION_EXACT TRUE)
  endif()
endif()

它只检查当前版本(9.0.1)是否小于请求的版本(任何以8开头的版本字符串)。由于9不小于8，所以将PACKAGE_VERSION_COMPATIBLE变量设置为true，并接受包。

当您指定EXACT时，STREQUAL比较将返回false，因此PACKAGE_VERSION_EXACT不会被设置为TRUE，因此将拒绝该包并考虑VTK 8包。

这是VTK 9的不幸行为，它不够复杂，不足以解释版本范围参数，它声称向后兼容所有以前的版本。

要强制在您的情况下使用VTK 8，您应该编写以下内容：

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find_package(VTK 8...<9 REQUIRED) 
if (VTK_VERSION VERSION_GREATER_EQUAL 9)
    message(FATAL_ERROR "This application requires VTK 8.x, but VTK ${VTK_VERSION} was found. Please set VTK_DIR to a folder containing the VTKConfig.cmake file from a VTK 8 installation.")
endif ()

然后可以在命令行设置-DVTK_DIR=/usr/local/lib/cmake/vtk-8.2。

票数 1
EN
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：

https://stackoverflow.com/questions/72409928

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