Adding a .projectile file causes "projectile-invalidate-cache: Wrong type argument: hash-table-p, nil"

[jwr]

Expected behavior

Adding a .projectile file to the root of a project should not stop projectile-find-file from working.

Actual behavior

Adding a .projectile file (either empty or containing excluded directories) to the root of a project causes projectile-find-file to fail with "Wrong type argument: hash-table-p, nil"

Steps to reproduce the problem

Add a .projectile file
run projectile-find-file

Environment & Version information

Projectile version information

Projectile 2.7.0

Emacs version

Emacs 29.1.50, earlier also on Emacs 28

Operating system

Mac OS 12.6.7

[Pacane]

I'm also hitting this issue. Do you have any workaround so far @jwr ?

[jwr]

Unfortunately, no. I learned to live with it and the pain of projectile-find-file listing a ton of irrelevant stuff.

[github-actions]

This issue has been automatically marked as stale because it has not had any recent activity. It will be closed soon if no further activity occurs. Thank you for your contribution and understanding!

[jwr]

This issue still exists for me. Emacs 29.1, Projectile 2.8.0, macOS 15.1.1.

I sadly cannot use a .projectile file to limit what gets considered for opening.

[jwr]

Here is a backtrace:

Debugger entered--Lisp error: (wrong-type-argument hash-table-p nil)
  remhash("/Users/jwr/Sync/code/" nil)
  projectile-invalidate-cache(nil)
  projectile-maybe-invalidate-cache(nil)
  (if (and (eq projectile-require-project-root 'prompt) (not (projectile-project-p))) (counsel-projectile-find-file-action-switch-project) (projectile-maybe-invalidate-cache arg) (+projectile-find-file--initialize) (let* ((project-files (+projectile-find-file--sort-file-with-scores (projectile-current-project-files))) (filename (completing-read (projectile-prepend-project-name "Find file: ") project-files nil t))) (if filename (progn (find-file (projectile-expand-root filename)))) (if nil (progn (ivy-read (projectile-prepend-project-name "Find file: ") project-files :matcher #'+projectile-find-file--matcher :require-match t :action counsel-projectile-find-file-action :caller '+projectile-find-file)))))
  +projectile-find-file(nil)
  funcall-interactively(+projectile-find-file nil)
  call-interactively(+projectile-find-file nil nil)
  command-execute(+projectile-find-file)

[bbatsov]

The problem seems to be triggered by:

(defun projectile-maybe-invalidate-cache (force)
  "Invalidate if FORCE or project's dirconfig newer than cache."
  (when (or force (file-newer-than-file-p (projectile-dirconfig-file)
                                          projectile-cache-file))
    (projectile-invalidate-cache nil)))

I'm puzzled how this happens in your case, though, as without a cache file this should never enter the projectile-invalidate-cache command when the error occurs.

[bbatsov]

I think I have a pretty good guess as to what's going on here. Would I be right if I assumed you're not using projectile-mode? I'm asking because I see some cache init logic is there and I'm guessing things break for people not using projectile-mode directly. Should be an easy fix, provided that's the root cause.

[jwr]

First, my apologies for an egg-on-face moment: what I initially reported was not about projectile-find-file, but about +projectile-find-file, which is part of a horrible hack to the default ranking of files in projectile. I've been using that code for years, as it vastly improves my experience with projectile-find-file. Notice the + in the backtraces above…

However.

When I use the actual projectile-find-file I can also reproduce the error. With your hint, I was able to debug and find out why projectile-invalidate-cache is called. It's because if I create a .projectile file (empty) in the current project, file-newer-than-file-p gets called with that .projectile file and projectile-cache-file which is ~/.emacs.d/projectile.cache which doesn't exist in my filesystem. file-newer-than-file-p returns t in this case, which causes the call to projectile-invalidate-cache.

If I touch ~/.emacs.d/projectile.cache, the problem disappears.

In other words: my initial report was garbage, but the problem still exists, even though I am not using the cache.

[jwr]

I think I have a pretty good guess as to what's going on here. Would I be right if I assumed you're not using projectile-mode?

That… is a trickier question than I imagined.

I never explicitly call projectile-mode and projectile-mode variable is nil.

but this is how I initialize projectile:

(use-package projectile
  :config
  (setq projectile-global-mode t
		projectile-current-dir-priority t
		projectile-sort-order 'modification-time))

[bbatsov]

I did some changes to the caching logic in 5061bd8 that I believe should solve your problem (amongst other problems).

[bbatsov]

At any rate - I think my last round of changes should have solved the problem for you.

[jwr]

I can confirm that projectile 2.9.1 fixes the problem! Thank you! 🙏