# Your CMakeCache.txt file was copied to CopyOfCMakeCache.txt. Please post that file on discourse.cmake.org.

**URL:** https://discourse.cmake.org/t/your-cmakecache-txt-file-was-copied-to-copyofcmakecache-txt-please-post-that-file-on-discourse-cmake-org/7630
**Category:** Usage
**Tags:** os:windows
**Created:** [March 8, 2023, 1:37pm UTC](https://discourse.cmake.org/t/your-cmakecache-txt-file-was-copied-to-copyofcmakecache-txt-please-post-that-file-on-discourse-cmake-org/7630 "2023-03-08T13:37:36Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![Jeslin](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/j/51bf81/32.png) [@Jeslin](https://discourse.cmake.org/u/Jeslin)
#### Post date: [March 8, 2023, 1:37pm UTC](https://discourse.cmake.org/t/your-cmakecache-txt-file-was-copied-to-copyofcmakecache-txt-please-post-that-file-on-discourse-cmake-org/7630/1 "2023-03-08T13:37:36Z")

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I am getting below error. Please help me to resolve

System is unknown to cmake, create:  
Platform/Windows to use this system, please post your config file on [discourse.cmake.org](http://discourse.cmake.org) so it can be added to cmake  
Your CMakeCache.txt file was copied to CopyOfCMakeCache.txt. Please post that file on [discourse.cmake.org](http://discourse.cmake.org).

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### Author: ![scivision](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/s/a87d85/32.png) [@scivision](https://discourse.cmake.org/u/scivision)
#### Post date: [March 9, 2023, 12:17am UTC](https://discourse.cmake.org/t/your-cmakecache-txt-file-was-copied-to-copyofcmakecache-txt-please-post-that-file-on-discourse-cmake-org/7630/2 "2023-03-09T00:17:09Z")

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That file would be in your build directory e.g. if you typed `cmake -B build` then the file is at build/CMakeCache.txt

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### Author: ![Jeslin](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/j/51bf81/32.png) [@Jeslin](https://discourse.cmake.org/u/Jeslin)
#### Post date: [March 9, 2023, 2:55am UTC](https://discourse.cmake.org/t/your-cmakecache-txt-file-was-copied-to-copyofcmakecache-txt-please-post-that-file-on-discourse-cmake-org/7630/3 "2023-03-09T02:55:53Z")

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As i am new to the CMake this answer is not clear to me. which file would be in build directory where i need to type cmake -B build

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### Author: ![ben.boeckel](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/b/ea5d25/32.png) [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)
#### Post date: [March 11, 2023, 12:58am UTC](https://discourse.cmake.org/t/your-cmakecache-txt-file-was-copied-to-copyofcmakecache-txt-please-post-that-file-on-discourse-cmake-org/7630/4 "2023-03-11T00:58:59Z")

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> [@Jeslin](#):
>
> which file would be in build directory

The build directory is where `CMakeCache.txt` is placed.

> [@Jeslin](#):
>
> where i need to type cmake -B build

You don’t need to type that. It’s a possibility of how you made the build directory. By default it is the current working directory of where you ran CMake itself (`-B` just sets it explicitly).