Linux (and other sorts of) distributions that ship your product will at times absorb bug reports since users tend to report them to their distro instead of the upstream project, and not all distros excel at passing on the bug reports to and cooperate with the upstream project (us).
This is good and meaningful when those bugs happen due to choices and details that were done by the distribution itself and are not actually bugs in the upstream project.
However, some legitimate bugs are reported by users but you never see them and they sit lingering and slowly rotting in someone else's bug tracker. In the best of days, someone there might eventually take pity and forward valid bugs to your project.
At times I have made it a habit of mine to regularly browse the bug trackers of those who seemed to accumulate the largest number of issues that concerned my projects and either engage with the reports there, or re-post worthwhile issues into the project's own bug tracker.