### Author:  [@craig.scott](https://discourse.cmake.org/u/craig.scott)
#### Post date: [May 3, 2024, 10:42pm UTC](https://discourse.cmake.org/t/error-using-fetchcontent-with-url/10788/2 "2024-05-03T22:42:35Z")
Do not use `${CMAKE_BINARY_DIR}` as the `SOURCE_DIR`. The `${CMAKE_BINARY_DIRECTORY}` is already something CMake populates with various things, and trying to make it your dependency’s source directory will cause corruption. You can specify a _subdirectory_ below `${CMAKE_BINARY_DIRECTORY}` though (and I do this in some projects). For example:
```cmake
FetchContent_Declare(MyDependency
URL my/dependency/resource.tar.gz
HTTP_HEADER "PRIVATE-TOKEN: " -L
SOURCE_DIR ${CMAKE_BINARY_DIR}/MyDependency
)
```
I’m also wondering about the `-L` at the end of the `HTTP_HEADER` line. That looks suspicious, it isn’t a HTTP header and looks more like a raw curl command line option, but CMake uses internal function calls directly in the C/C++ layer for its networking.
---
### Author:  [@Dylan\_Reedy](https://discourse.cmake.org/u/Dylan_Reedy)
#### Post date: [May 6, 2024, 8:06pm UTC](https://discourse.cmake.org/t/error-using-fetchcontent-with-url/10788/3 "2024-05-06T20:06:06Z")
Hi Craig, thanks for the response.
My issue is mostly that pre-existing legacy systems require that these artifacts be located in the same directory, not a subdirectory or a parallel one. The old systems use python scripts to fetch dependencies, and I’m trying to unify everything in CMake. This only has to be done after the build is complete (at application runtime). Would you recommend a custom command to do this after the build is complete? I suppose I could create symlinks to the directory as well.
Regarding the `-L`, my code above works but definitely does _not_ work without the `-L`. 🤷
---
### Author:  [@craig.scott](https://discourse.cmake.org/u/craig.scott)
#### Post date: [May 6, 2024, 10:07pm UTC](https://discourse.cmake.org/t/error-using-fetchcontent-with-url/10788/4 "2024-05-06T22:07:12Z")
Do you need the sources or the built binaries to all be located in the same directory? Those are two very different scenarios.
> Regarding the `-L` , my code above works but definitely does _not_ work without the `-L` .
I assume you’re using that to convince the implementation to follow redirections. I’d have to crawl through the implementation to find out if there’s an officially supported way to achieve that. I’m kinda surprised this works though, I would have expected it to cause an error (it _should_ cause an error, since `-L` is not a valid HTTP header). Take this as a warning that using `-L` might stop working at any time with a future update to CMake.
---
### Author:  [@Dylan\_Reedy](https://discourse.cmake.org/u/Dylan_Reedy)
#### Post date: [May 7, 2024, 12:39am UTC](https://discourse.cmake.org/t/error-using-fetchcontent-with-url/10788/5 "2024-05-07T00:39:21Z")
> Take this as a warning that using `-L` might stop working at any time with a future update to CMake.
Understood.
> Do you need the sources or the built binaries to all be located in the same directory? Those are two very different scenarios.
We need the binaries of the dependencies (prebuilt, stored in a generic gitlab package repository) to be located in the same directory as our project’s built binaries.