[feature] Add the possibility to choose exact package version with tools.system.package_manager

[CommanderCRM]

What is your suggestion?

Hi!

I've read the documentation for package_manager module, tried it in recipes and read the source code of the module.
Nowhere to be found is the ability to choose the exact version of the package that system needs to install.

For the apt or apt-get interface it is possible to provide the version in the following way:
apt-get install package=X.Y.Z

For choco:
choco install package --version=X.Y.Z

I don't know any Linux\Windows\MacOS package managers (including brew\macports) which don't provide this ability.
So is there any chance for it to be added to Conan?

Have you read the CONTRIBUTING guide?

• I've read the CONTRIBUTING guide

[memsharded]

Hi @CommanderCRM

Thanks for the feedback.

So far this hasn't been a need, because the tools.system.package_manager functionality is focused on "system" packages that are very challenging to be implemented as Conan packages and be versioned with them.
The usages in ConanCenter are for example things like xorg or opengl, which usually comes very defined by the Linux distribution that is running, it is not that selecting different versions is always possible.

And for other more regular system packages that could have several versions, this approach can easily lead to issues with system versions, for example if 2 different Conan packages installed different versions of the same system package, that could produce inconsistencies and problems if those 2 packages are used in the same project. And tracking the system packages versions to detect conflicts is not planned. This is why Conan users mostly create Conan packages for the kind of thing that can be easily versioned and it is not very integrated with the system to be managed externally.

Said that, I am not opposed to have this functionality, but given the usage so far, this wouldn't be a priority for the team. If some users are willing to contribute such functionality, it should cover the cases that _SystemPackageManagerTool is covering, that is: "check", "install", "update", and the different modes that tools.system.package_manager:mode provides: "check", "install", "report" and "report-installed". It could be integrated in the current package name such apt.install(["pkg1", "pkg2"]) => apt.install(["pkg1=version1", "pkg2=version2"]), and that can be parsed internally in case it is necessary. In any case, this would still be a thin wrapper over the system package manager command, no other functionality as version conflict or the like should be considered.