cmake config_error ai_generated true

CMake Warning (dev): Policy CMP0077 is not set: option() honors normal variables. Run "cmake --help-policy CMP0077" for policy details. Use the cmake_policy command to set the policy and suppress this warning.

ID: cmake/policy-cmp0077-not-set

Also available as: JSON · Markdown · 中文
90%Fix Rate
84%Confidence
1Evidence
2023-07-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
CMake 3.13 active — — —
CMake 3.14 active — — —
CMake 3.20 active — — —

Root Cause

CMake policy CMP0077 is not explicitly set, causing option() to behave inconsistently when a normal variable with the same name exists.

generic

中文

未显式设置CMake策略CMP0077，导致当存在同名普通变量时，option()行为不一致。

Official Documentation

https://cmake.org/cmake/help/latest/policy/CMP0077.html

Workarounds

  1. 95% success Set the policy to NEW at the beginning of CMakeLists.txt: cmake_policy(SET CMP0077 NEW) 
    Set the policy to NEW at the beginning of CMakeLists.txt: cmake_policy(SET CMP0077 NEW)
  2. 80% success If the old behavior is needed, set to OLD: cmake_policy(SET CMP0077 OLD), but this is not recommended for new projects. 
    If the old behavior is needed, set to OLD: cmake_policy(SET CMP0077 OLD), but this is not recommended for new projects.

中文步骤

  1. 在CMakeLists.txt开头设置策略为NEW：cmake_policy(SET CMP0077 NEW)
  2. 如果需要旧行为，设置为OLD：cmake_policy(SET CMP0077 OLD)，但不推荐用于新项目。

Dead Ends

Common approaches that don't work:

  1. 40% fail

    The warning may lead to subtle bugs where option() does not behave as expected, especially in cache variable scenarios.

  2. 50% fail

    OLD behavior may break modern CMake patterns and cause unexpected cache variable behavior.