A /libx report client command that takes a mod id and then gathers important information about that mod and its dependencies. Maybe also the whole mod list. This metadata should be saved onto a paste site.

If the issue tracker, the mod has in its metadata is a github URL, a link should be provided, that creates an issue with the newly created paste of the metadata and an instruction (in form of an html comment) that states that the latest log should be uploaded. This may include a link to https://git.io/mclogs

For the github issue URLs see here. A problem with this is that if a mod uses issue templates (which most mods do), these links won't work. It might be a good thing to detect the available templates and pick one named something like bug if possible.

Also for modpacks it might be a good thing to have their own issue tracker for modpack problems. So maybe there could be a config for modpacks to add a link to their issue tracker that will be used when no argument is provided to the command.

Also the special case minecraft should be considered which should link to https://bugs.mojang.com and should not create a paste.

It might also be worth thinking about an API for other mods to add their own issue creation logic.