Clear the return variable from the CMake cache

[TimeLooper]

No description provided.

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[TimeLooper]

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[rsomla1]

What is the problem this is fixing?

[TimeLooper]

When I used this cmake file to import the JDBC library, the actual linked file in the final generated vcxproj file was mysqlcppconnx.lib, not mysqlcppconn.lib. This was because the function was called twice to obtain the file paths of the two libraries, resulting in the second direct read of the cmake cache and ultimately causing an error. 原始邮件 发件人：Rafal Somla ***@***.***> 发件时间：2025年3月20日 23:23 收件人：mysql/mysql-connector-cpp ***@***.***> 抄送：TimeLooper ***@***.***>, Author ***@***.***> 主题：Re: [mysql/mysql-connector-cpp] Clear the return variable from theCMake cache (PR #37) @rsomla1 commented on this pull request. In mysql-concpp-config.cmake.in: > @@ -880,6 +880,7 @@ function(find_imp_lib var base_name path)   set(CMAKE_FIND_LIBRARY_SUFFIXES .lib)   #message("!!! Looking for import library for: ${path}") +  unset(${var} CACHE) What is the problem this is fixing? — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you authored the thread.

[rsomla1]

When I used this cmake file to import the JDBC library, the actual linked file in the final generated vcxproj file was mysqlcppconnx.lib, not mysqlcppconn.lib. This was because the function was called twice to obtain the file paths of the two libraries, resulting in the second direct read of the cmake cache and ultimately causing an error.

Right. I asked because the find_library() invocation explicitly says NO_CACHE to prevent storing the value of ${var} in the cache.

  find_library(${var}
    NAMES ${base_name}
    PATHS ${base_path}
    PATH_SUFFIXES ${vs_suffix}
    NO_DEFAULT_PATH
    NO_CACHE
  )

However, I checked that NO_CACHE option requires cmake version 3.21+ and we try to support 3.15 at this point. So I will merge your fix and also do similar thing in few other places where NO_CACHE is used. Thanks for the patch!