xref-find-definitions with multiple active projects

I'm not an emacs power user nor very proficient at elisp. I use magit quite heavily in emacs, and I'm regularly working on multiple git repositories at the same time. These are different repositories/worktrees for the same project, just with different branches checked out. I'm not sure if it is relevant, but these are Perl projects, using cperl-mode, and each project has a single TAGS files at the project root. The first time I use \`M-.\` (\`xref-find-definitions\`), I get prompted to load a TAGS file, and I select the one for the current repository I'm using. This works as expected. However when I happen to be editing a file from a different repository and hit M-., the previously loaded TAGS file is still used, so this brings me to the source file from the wrong repository. Since the files look identical, I don't notice this and regularly make edits in the wrong git worktree. I saw that I can load multiple tags tables using visit-tags-table, and then switch between them using select-tags-table. Is there any way to automate this so that when I use \`M-.\` it automatically chooses the TAGS file closest to the current file path? I looked into project.el and projectile, but I couldn't find any examples for how to do this.

https://github.com/redguardtoo/counsel-etags , it automatically picks up right tags per project.

I suspect it will require a different xref backend, or a modification of the existing one. Someone could monkeypatch that with third-party code, but `M-x report-emacs-bug` might get you there as well.

Thanks for the suggestion. I gave this a try, but I couldn't get it to pick up the existing TAGS files. It kept falling back to a grep. I also didn't see a way to jump to the definition of a function. It looks like it was just searching for references, which you then need to wade through to find which one is the definition.

It automatically detects the TAGS in project root folder. It falls back to grep if the definition does not exist in TAGS. So you need check TAGS.

Give citre a try. Citre picks up tags depending on the project root automatically, and provides you find definitions and completions easily (and even references if using gnu global)