[cmake-developers] automatically download library

[Ryan Schmidt]

On Oct 8, 2015, at 10:06 AM, Marsel Galimullin wrote:

> The idea is that CMake has possibility to contact with package managers for download necessary libraries.
> If “find_package” can’t find a library, it need to call apt-get install.
> Example:
>    auto_downland(apt-get)
>    find_package (Boost COMPONENTS system thread REQUIRED)

I understand the idea, and I'm telling you that if you need this for your own personal project -- one that will never be included in a package management system -- then do whatever you like. But if you are proposing this as something that should be included in cmake, and you are suggesting that it could be used by any project that wants to -- even in projects that might someday be included in a package management system -- then I can tell you that this would not be welcomed by the people who maintain those package management systems. I am such a person. If I were tasked with the request to add to my package management system a project that wanted to control the installation of its own dependencies, or that in some other way tried to be in charge of downloading its dependencies, I would either have to rip all that code out, or more likely I would reject the request to add that project as being too labor-intensive. It is the package management system's job to download and install dependencies, not the job of the project's build system.