CMake报错：Debug配置下导入目标fmt::fmt未设置IMPORTED_LOCATION

问题详情 #

编译时遇到CMake错误：

[cmake] CMake Error in CMakeLists.txt:
[cmake] IMPORTED_LOCATION not set for imported target "fmt::fmt" configuration
[cmake] "Debug".

已通过以下命令安装fmtlib：

$ sudo cmake --install . --config Debug
-- Installing: /usr/local/lib/libfmt.so.9.1.1
-- Installing: /usr/local/lib/libfmt.so.9
-- Installing: /usr/local/lib/libfmt.so
-- Installing: /usr/local/include/fmt/args.h
-- Installing: /usr/local/include/fmt/chrono.h
-- Installing: /usr/local/include/fmt/color.h
-- Installing: /usr/local/include/fmt/compile.h
-- Installing: /usr/local/include/fmt/core.h
-- Installing: /usr/local/include/fmt/format.h
-- Installing: /usr/local/include/fmt/format-inl.h
-- Installing: /usr/local/include/fmt/os.h
-- Installing: /usr/local/include/fmt/ostream.h
-- Installing: /usr/local/include/fmt/printf.h
-- Installing: /usr/local/include/fmt/ranges.h
-- Installing: /usr/local/include/fmt/std.h
-- Installing: /usr/local/include/fmt/xchar.h
-- Installing: /usr/local/lib/cmake/fmt/fmt-config.cmake
-- Installing: /usr/local/lib/cmake/fmt/fmt-config-version.cmake
-- Installing: /usr/local/lib/cmake/fmt/fmt-targets.cmake
-- Installing: /usr/local/lib/pkgconfig/fmt.pc

当前CMakeLists.txt内容：

cmake_minimum_required (VERSION 3.20)
project (Test)
set(CMAKE_CXX_STANDARD 23)
add_executable(main main.cpp)
find_package(fmt)
target_link_libraries(main fmt::fmt)

问题原因 #

在类Unix系统（如Linux）中，CMake默认采用单配置模式，不区分Debug/Release版本。你安装fmt时指定了--config Debug，导致生成的fmt-targets.cmake中错误地尝试为Debug配置单独设置导入路径，但实际上仅安装了单版本的库，最终引发该错误。

解决方案 #

方法1：修改CMakeLists.txt，修复导入目标配置 #

在find_package后添加逻辑，为Debug配置复用Release版本的库路径：

cmake_minimum_required (VERSION 3.20)
project (Test)
set(CMAKE_CXX_STANDARD 23)
add_executable(main main.cpp)

find_package(fmt REQUIRED)
# 针对单配置系统，为Debug配置设置导入位置
if(TARGET fmt::fmt)
  get_target_property(FMT_RELEASE_LIB fmt::fmt IMPORTED_LOCATION_RELEASE)
  if(FMT_RELEASE_LIB)
    set_target_properties(fmt::fmt PROPERTIES
      IMPORTED_LOCATION_DEBUG "${FMT_RELEASE_LIB}"
    )
  endif()
endif()

target_link_libraries(main PRIVATE fmt::fmt)

方法2：重新安装fmtlib，移除--config Debug参数 #

类Unix系统无需指定配置类型，直接执行：

sudo cmake --install .

默认安装的是Release版本库，CMake会自动生成正确的目标配置文件，无需区分Debug/Release。

方法3：明确指定find_package的配置 #

修改find_package命令，强制使用单配置的fmt：

cmake_minimum_required (VERSION 3.20)
project (Test)
set(CMAKE_CXX_STANDARD 23)
add_executable(main main.cpp)

# 指定REQUIRED确保找到fmt，可添加版本号约束
find_package(fmt 9 REQUIRED CONFIG CONFIGS fmt-config.cmake)
target_link_libraries(main PRIVATE fmt::fmt)

内容的提问来源于stack exchange，提问作者Tom Huntington