# some question

**URL:** https://discourse.cmake.org/t/some-question/2227
**Category:** Usage
**Tags:** os:windows
**Created:** [November 24, 2020, 3:03pm UTC](https://discourse.cmake.org/t/some-question/2227 "2020-11-24T15:03:07Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![cuger\_k](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/c/7ab992/32.png) [@cuger\_k](https://discourse.cmake.org/u/cuger_k)
#### Post date: [November 24, 2020, 3:03pm UTC](https://discourse.cmake.org/t/some-question/2227/1 "2020-11-24T15:03:08Z")

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![image](https://discourse.cmake.org/uploads/default/original/1X/4ffa6ca1ff406cb2e6787480e9bfee4bc36df2af.png) When I run the example, an error appears in the figure. Does anyone know what happened?

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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: [November 25, 2020, 5:25pm UTC](https://discourse.cmake.org/t/some-question/2227/2 "2020-11-25T17:25:57Z")

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My guess is that you specified `RenderCylinder.cpp` as a source to a file, but it does not exist (yet). You’ll need to make the file before CMake can determine what to do with it.