cmake config_error ai_generated true

CMake Error: Feature cxx_std_17 is not available for compiler "GNU" version 4.8.

ID: cmake/compiler-feature-request-failed

Also available as: JSON · Markdown · 中文
90%Fix Rate
87%Confidence
1Evidence
2024-02-28First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
GCC 4.8 active — — —
GCC 5.4 active — — —
Clang 3.5 active — — —

Root Cause

A target or project requests a C++ standard feature (e.g., cxx_std_17) that the installed compiler does not support due to its old version.

generic

中文

目标或项目请求了一个 C++ 标准功能（例如 cxx_std_17），但安装的编译器版本太旧，不支持该功能。

Official Documentation

https://cmake.org/cmake/help/latest/manual/cmake-compile-features.7.html

Workarounds

  1. 95% success Upgrade the compiler to a version that supports C++17 (e.g., GCC 7 or later). Alternatively, set the target to a lower standard: set_target_properties(mytarget PROPERTIES CXX_STANDARD 14). 
    Upgrade the compiler to a version that supports C++17 (e.g., GCC 7 or later). Alternatively, set the target to a lower standard: set_target_properties(mytarget PROPERTIES CXX_STANDARD 14).
  2. 90% success Use target_compile_features(mytarget PRIVATE cxx_std_14) instead of cxx_std_17, and adjust code accordingly. Example: target_compile_features(mytarget PRIVATE cxx_std_14). 
    Use target_compile_features(mytarget PRIVATE cxx_std_14) instead of cxx_std_17, and adjust code accordingly. Example: target_compile_features(mytarget PRIVATE cxx_std_14).
  3. 85% success If compiler upgrade is not possible, use a compatibility layer or conditionally compile C++17 features: if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 7.0) target_compile_features(mytarget PRIVATE cxx_std_17) endif(). 
    If compiler upgrade is not possible, use a compatibility layer or conditionally compile C++17 features: if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 7.0) target_compile_features(mytarget PRIVATE cxx_std_17) endif().

中文步骤

  1. 升级编译器到支持 C++17 的版本（例如 GCC 7 或更高）。或者，将目标设置为较低标准：set_target_properties(mytarget PROPERTIES CXX_STANDARD 14)。
  2. 使用 target_compile_features(mytarget PRIVATE cxx_std_14) 代替 cxx_std_17，并相应调整代码。示例：target_compile_features(mytarget PRIVATE cxx_std_14)。
  3. 如果无法升级编译器，使用兼容层或条件编译 C++17 特性：if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 7.0) target_compile_features(mytarget PRIVATE cxx_std_17) endif()。

Dead Ends

Common approaches that don't work:

  1. 80% fail

    The compiler still does not support C++17; code using C++17 features will fail to compile with cryptic errors.

  2. 75% fail

    CMake will still detect the compiler version and may produce warnings; also, compiler may not fully support C++17.