我正在使用/usr/lib在pc上交叉编译一个库(ORBSLAM3(来自rpi4(使用rsync后(。我把它们放在一个名为"；rootf"；。先决条件库以前已经安装过，所以它们现在位于~/rootf/usr和~/rootf/lib中。我需要使用~/rootf/作为根来编译ORBSLAM3。
问题是我不熟悉cmake，所以我已经挣扎了一段时间。
编译过程如下：
- 在ORBSLAM3的顶层使用Toolchain-rpi.CMakeLists.txt
- 在CMakeLists.txt中，它通过find_package查找穿山甲(需要穿山甲(
find_package((实际上做得很好。成功找到
/home/ethan/raspberrypi/rootfs/usr/local/lib/cmake/Pangolin/PangolinTargets.cmake
该CMakeLists.txt中的CMAKE_PREFIX_PATH是正确的，即
/home/ethan/raspberrypi/rootfs/usr/local/lib;/home/ethan/raspberrypi/rootfs/usr/lib/arm-linux-gnueabihf
在我卸载ubuntu上的穿山甲后，我得到了这个：
CMake Error at /home/ethan/raspberrypi/rootfs/usr/local/lib/cmake/Pangolin/PangolinTargets.cmake:80 (message):
The imported target "pangolin" references the file
"/usr/local/lib/libpangolin.so"
but this file does not exist. Possible reasons include:
* The file was deleted, renamed, or moved to another location.
由于Pangolin最初安装在船上，所以船上的libpangolin.so位于/usr/local/lib/libpangoline.so。我想当我使用PangolinTargets.cmake时，它也在做同样的事情。
我在PangolinTargets.CMAKE中输出CMAKE_SYSROOT、CMAKE_PREFIX_PATH、_IMPORT_PREFIX。这就是我所期望的。
CMAKE_SYSROOT = /home/ethan/raspberrypi/rootfs
CMAKE_PREFIX_PATH = ;/home/ethan/raspberrypi/rootfs/usr/local/lib;/home/ethan/raspberrypi/rootfs/usr/lib/arm-linux-gnueabihf
_IMPORT_PREFIX = /home/ethan/raspberrypi/rootfs/usr/local
即使我在下面的路径中添加/home/ehan/rraspberrypi/rootfs作为前缀，也没有任何变化。
set_target_properties(pangolin PROPERTIES
INTERFACE_INCLUDE_DIRECTORIES "/usr/include;/usr/include;/usr/include;/usr/local/include/eigen3;${_IMPORT_PREFIX}/include"
INTERFACE_LINK_LIBRARIES "rt;pthread;/usr/lib/arm-linux-gnueabihf/libGL.so;/usr/lib/arm-linux-gnueabihf/libGLU.so;
INTERFACE_SYSTEM_INCLUDE_DIRECTORIES "/usr/include;/usr/include;/usr/include;/usr/local/include/eigen3"
)
以下是PangolinTargets.cmake的内容。我不确定哪些部分导致只搜索/usr/。谢谢大家。
# Generated by CMake
if("${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}" LESS 2.5)
message(FATAL_ERROR "CMake >= 2.6.0 required")
endif()
cmake_policy(PUSH)
cmake_policy(VERSION 2.6)
#----------------------------------------------------------------
# Generated CMake target import file.
#----------------------------------------------------------------
# Commands may need to know the format version.
set(CMAKE_IMPORT_FILE_VERSION 1)
# Protect against multiple inclusion, which would fail when already imported targets are added once more.
set(_targetsDefined)
set(_targetsNotDefined)
set(_expectedTargets)
foreach(_expectedTarget pangolin)
list(APPEND _expectedTargets ${_expectedTarget})
if(NOT TARGET ${_expectedTarget})
list(APPEND _targetsNotDefined ${_expectedTarget})
endif()
if(TARGET ${_expectedTarget})
list(APPEND _targetsDefined ${_expectedTarget})
endif()
endforeach()
if("${_targetsDefined}" STREQUAL "${_expectedTargets}")
unset(_targetsDefined)
unset(_targetsNotDefined)
unset(_expectedTargets)
set(CMAKE_IMPORT_FILE_VERSION)
cmake_policy(POP)
return()
endif()
if(NOT "${_targetsDefined}" STREQUAL "")
message(FATAL_ERROR "Some (but not all) targets in this export set were already defined.nTargets Defined: ${_targetsDefined}nTargets not yet defined: ${_targetsNotDefined}n")
endif()
unset(_targetsDefined)
unset(_targetsNotDefined)
unset(_expectedTargets)
# Compute the installation prefix relative to this file.
get_filename_component(_IMPORT_PREFIX "${CMAKE_CURRENT_LIST_FILE}" PATH)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
if(_IMPORT_PREFIX STREQUAL "/")
set(_IMPORT_PREFIX "")
endif()
# Create imported target pangolin
add_library(pangolin SHARED IMPORTED)
set_target_properties(pangolin PROPERTIES
INTERFACE_INCLUDE_DIRECTORIES "/usr/include;/usr/include;/usr/include;/usr/local/include/eigen3;${_IMPORT_PREFIX}/include"
INTERFACE_LINK_LIBRARIES "rt;pthread;/usr/lib/arm-linux-gnueabihf/libGL.so;/usr/lib/arm-linux-gnueabihf/libGLU.so;/usr/lib/arm-linux-gnueabihf/libGLEW.so;/usr/lib/arm-linux-gnueabihf/libEGL.so;/usr/lib/arm-linux-gnueabihf/libSM.so;/usr/lib/arm-linux-gnueabihf/libICE.so;/usr/lib/arm-linux-gnueabihf/libX11.so;/usr/lib/arm-linux-gnueabihf/libXext.so;rt;pthread;/usr/lib/arm-linux-gnueabihf/libdc1394.so;/usr/lib/arm-linux-gnueabihf/libpng.so;/usr/lib/arm-linux-gnueabihf/libz.so;/usr/lib/arm-linux-gnueabihf/libjpeg.so;/usr/lib/arm-linux-gnueabihf/libtiff.so;/usr/lib/arm-linux-gnueabihf/libIlmImf.so"
INTERFACE_SYSTEM_INCLUDE_DIRECTORIES "/usr/include;/usr/include;/usr/include;/usr/local/include/eigen3"
)
if(CMAKE_VERSION VERSION_LESS 2.8.12)
message(FATAL_ERROR "This file relies on consumers using CMake 2.8.12 or greater.")
endif()
# Load information for each installed configuration.
get_filename_component(_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
file(GLOB CONFIG_FILES "${_DIR}/PangolinTargets-*.cmake")
foreach(f ${CONFIG_FILES})
include(${f})
endforeach()
# Cleanup temporary variables.
set(_IMPORT_PREFIX)
# Loop over all imported files and verify that they actually exist
foreach(target ${_IMPORT_CHECK_TARGETS} )
foreach(file ${_IMPORT_CHECK_FILES_FOR_${target}} )
if(NOT EXISTS "${file}" )
message(FATAL_ERROR "The imported target "${target}" references the file
"${file}"
but this file does not exist. Possible reasons include:
* The file was deleted, renamed, or moved to another location.
* An install or uninstall procedure did not complete successfully.
* The installation package was faulty and contained
"${CMAKE_CURRENT_LIST_FILE}"
but not all the files it references.
")
endif()
endforeach()
unset(_IMPORT_CHECK_FILES_FOR_${target})
endforeach()
unset(_IMPORT_CHECK_TARGETS)
# This file does not depend on other imported targets which have
# been exported from the same project but in a separate export set.
# Commands beyond this point should not need to know the version.
set(CMAKE_IMPORT_FILE_VERSION)
cmake_policy(POP)
如何显示我们使用find_package((搜索的文件的路径？
CMAKE_PREFIX_PATH
用分号分隔的目录列表，指定find_package((要搜索的安装前缀。。。
set(CMAKE_PREFIX_PATH /home/users/rootf/usr/local/lib)
# additionalllly I also do a precaution
set(CMAKE_IGNORE_PATH / /bin /include /usr/lib /usr/local/lib)
您也可以使用CMAKE_FIND_USE_*_PATH变量进行操作。