Skip unreadable directories in projectile-index-directory (#1873)

Wrap the directory-files call in ignore-errors so that unreadable
directories (e.g. .Spotlight-V100 on macOS) are silently skipped
instead of aborting the entire native indexing operation.

Author: bbatsov

CHANGELOG.md

@@ -8,6 +8,7 @@
 
 ### Bugs fixed
 
+* [#1873](https://github.com/bbatsov/projectile/issues/1873): Skip unreadable directories during native indexing instead of aborting with a permission error.
 * [#1961](https://github.com/bbatsov/projectile/issues/1961): Prevent directories from matching file-type project root markers (e.g., a `workspace` directory no longer matches the `WORKSPACE` Bazel marker on case-insensitive filesystems).
 * [#1749](https://github.com/bbatsov/projectile/issues/1749): Strip `./` prefix from `fd` output in `projectile-files-via-ext-command`, fixing compatibility with older `fd` versions that don't support `--strip-cwd-prefix`.
 

projectile.el

@@ -1524,7 +1524,10 @@ IGNORED-DIRECTORIES may optionally be provided."
                         (projectile-index-directory f patterns progress-reporter ignored-files ignored-directories globally-ignored-directories))
                     (unless (projectile-ignored-file-p f ignored-files)
                       (list f))))))
-            (directory-files directory t)))))
+            ;; Use ignore-errors to skip unreadable directories (e.g.
+            ;; .Spotlight-V100 on macOS) instead of aborting the entire
+            ;; indexing operation.
+            (ignore-errors (directory-files directory t))))))
 
 ;;; Alien Project Indexing
 ;;

test/projectile-test.el

@@ -532,6 +532,25 @@ Just delegates OPERATION and ARGS for all operations except for`shell-command`'.
     (let ((projectile-indexing-method 'hybrid))
       (expect (projectile-dir-files "/my/root/") :to-equal '("a/b/c" "a/d/e")))))
 
+(describe "projectile-index-directory"
+  (it "skips unreadable directories"
+    (unless (eq system-type 'windows-nt)
+      (projectile-test-with-sandbox
+       (projectile-test-with-files
+        ("project/"
+         "project/.projectile"
+         "project/readable-file.el"
+         "project/unreadable-dir/")
+        (let* ((project-dir (file-name-as-directory (expand-file-name "project")))
+               (unreadable-dir (expand-file-name "unreadable-dir" project-dir))
+               (progress-reporter (make-progress-reporter "Indexing...")))
+          (set-file-modes unreadable-dir #o000)
+          (unwind-protect
+              (let ((files (projectile-index-directory project-dir nil progress-reporter)))
+                (expect (cl-some (lambda (f) (string-match-p "readable-file" f)) files) :to-be-truthy)
+                (expect (cl-some (lambda (f) (string-match-p "unreadable-dir" f)) files) :not :to-be-truthy))
+            (set-file-modes unreadable-dir #o755))))))))
+
 (describe "projectile-get-sub-projects-command"
   (it "gets sub projects command for git"
     (expect (string-prefix-p "git" (projectile-get-sub-projects-command 'git)) :to-be-truthy))