# Cannot use MSVC\_IDE before first project call?
**URL:** https://discourse.cmake.org/t/cannot-use-msvc-ide-before-first-project-call/2734
**Category:** Usage
**Tags:** gen:vs
**Created:** [February 10, 2021, 6:48pm UTC](https://discourse.cmake.org/t/cannot-use-msvc-ide-before-first-project-call/2734 "2021-02-10T18:48:20Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@YMba9g8j9CJp0wLoQf5y](https://discourse.cmake.org/u/YMba9g8j9CJp0wLoQf5y)
#### Post date: [February 10, 2021, 6:48pm UTC](https://discourse.cmake.org/t/cannot-use-msvc-ide-before-first-project-call/2734/1 "2021-02-10T18:48:20Z")
I’m writing a toolchain file and want to use the MSVC\_IDE variable. However it doesn’t work.
This will not work.
```auto
if (MSVC_IDE)
message(FATAL_ERROR "Foo")
endif()
```
This will work
```auto
if (CMAKE_GENERATOR MATCHES "Visual Studio")
message(FATAL_ERROR "Foo")
endif()
```
Is there a reason why?
---
### Author:  [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)
#### Post date: [February 10, 2021, 7:12pm UTC](https://discourse.cmake.org/t/cannot-use-msvc-ide-before-first-project-call/2734/2 "2021-02-10T19:12:36Z")
Hmm. That is set in `Modules/Platform/Windows-MSVC.cmake` using the same conditional as you have here. Are you, perhaps, using `clang-cl`?
Cc: @brad.king
---
### Author:  [@YMba9g8j9CJp0wLoQf5y](https://discourse.cmake.org/u/YMba9g8j9CJp0wLoQf5y)
#### Post date: [February 10, 2021, 7:15pm UTC](https://discourse.cmake.org/t/cannot-use-msvc-ide-before-first-project-call/2734/3 "2021-02-10T19:15:31Z")
No I’m using MSVC.
---
### Author:  [@YMba9g8j9CJp0wLoQf5y](https://discourse.cmake.org/u/YMba9g8j9CJp0wLoQf5y)
#### Post date: [February 10, 2021, 10:17pm UTC](https://discourse.cmake.org/t/cannot-use-msvc-ide-before-first-project-call/2734/4 "2021-02-10T22:17:00Z")
This problem isn’t exclusive to toolchains it’s any logic executed before the first project call.
---
### Author:  [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)
#### Post date: [February 10, 2021, 10:39pm UTC](https://discourse.cmake.org/t/cannot-use-msvc-ide-before-first-project-call/2734/5 "2021-02-10T22:39:32Z")
Oh! I missed the “toolchain” part, sorry 🤦♂️. Yes, the file I linked to is only run at compiler detection time, so yes, it is unavailable to toolchain files. That said, I don’t know how much more work that variable is going to carry, so the `CMAKE_GENERATOR`-based detection is likely the way to go.
---
### Author:  [@YMba9g8j9CJp0wLoQf5y](https://discourse.cmake.org/u/YMba9g8j9CJp0wLoQf5y)
#### Post date: [February 10, 2021, 10:44pm UTC](https://discourse.cmake.org/t/cannot-use-msvc-ide-before-first-project-call/2734/6 "2021-02-10T22:44:39Z")
Hm gotcha. That’s fine for me. I’d just suggest adding some documentation to clarify this. In case someone runs into this again.
---
### Author:  [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)
#### Post date: [February 10, 2021, 11:21pm UTC](https://discourse.cmake.org/t/cannot-use-msvc-ide-before-first-project-call/2734/7 "2021-02-10T23:21:42Z")
[https://gitlab.kitware.com/cmake/cmake/-/merge\_requests/5800](https://gitlab.kitware.com/cmake/cmake/-/merge_requests/5800)