# \--config since 3.20

**URL:** <https://discourse.cmake.org/t/config-since-3-20/3446>\
**Category:** Code\
**Created:** [May 31, 2021, 5:56pm UTC](https://discourse.cmake.org/t/config-since-3-20/3446 "2021-05-31T17:56:56Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Sergey\_K](https://discourse.cmake.org/user_avatar/discourse.cmake.org/sergey_k/32/1489_2.png) [@Sergey\_K](https://discourse.cmake.org/u/Sergey_K)\
**Post date:** [May 31, 2021, 5:56pm UTC](https://discourse.cmake.org/t/config-since-3-20/3446/1 "2021-05-31T17:56:56Z")

</div>

A few days ago I updated from 3.19 to 3.20 and my project failed to build because I use `ExternalProject_Add` and pass `--config` to subrojects, but `--config` has gone. For example, if we run cmake this way:

```auto
$ cmake --config

```

It will first complain about unknown option:

```auto
CMake Error: Unknown argument --config
CMake Error: Run 'cmake --help' for all supported options.

```

Latest documentation and release notes say nothing about `--config` removal.

What should I use instead of it?

---

<div class="post-metadata">

**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:** [May 31, 2021, 6:05pm UTC](https://discourse.cmake.org/t/config-since-3-20/3446/2 "2021-05-31T18:05:45Z")

</div>

`--config` never existed like that (a standalone flag). CMake prior to 3.20 pretty much ignored unknown arguments and the command line parser has been changed to actually detect such issues rather than silently accepting them.