No further undo information

[agzam]

I'm sure this is an upstream issue, I'm posting it here hoping someone would shed a light to it

I use evil and undo things in NORMAL mode pressing u (nothing unusual).

I have noticed that lately, I'm hitting the point where it simply says No further undo information and the stuff is simply lost. It's not in undo-tree either. I know, there are various vars like undo-limit that can be tweaked, but I haven't changed anything in my config. And it seems lately I'm hitting the limit fairly often - like I'd make about 10-20 changes, try to undo and bam! see the message, which is very frustrating and strange.

Does anyone else have the same problem?

[duianto]

The last comment in this issue:
unrecognized entry in undo list undo-tree-canary #9903
said that disabling this variable has fixed an undo issue (it might not be the same as yours):

(setq undo-tree-enable-undo-in-region nil)

Here's some more info about the variable:

(setq undo-tree-enable-undo-in-region nil)

See: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=16377#55

Quote from Dr. Cubitt:

No, the new error checking just helpfully revealed an existing bug in
undo-tree's undo-in-region support (which frankly has always been flaky,
as it's extraordinarily difficult to reliably reproduce undo
bugs). There's even an `undo-tree-enable-undo-in-region' toggle to
disable undo-in-region support, for exactly this reason. Probably I
should make it default to "off" for now.

source: emacs-evil/evil#1074 (comment)

I haven't read all of the links from those issues, but I noticed this comment: #774 (comment)

A new package https://github.com/jackkamm/undo-propose-el has been released and claims to be safer to use than undo-tree.

It might also be something to test.

[agzam]

Yeah I did find that issue and set the variable to nil, but I don't think it fixed it for me. I still feel I hit the limit too early, but at this point it's all just empirical observation, I don't have any proof that it was better and now it has gotten worse.

[agzam]

undo-propose seems to be nice, maybe even better than undo-tree but I'm afraid the latter is lodged in Spacemacs ecosystem and it wouldn't be very straightforward to replace one package with another, I might be wrong though.

[duianto]

There seems to be a newer version 0.6.6 of undo-tree than what's available on elpa (0.6.5) (where Spacemacs probably is pulling it from), there's more info here: #9903 (comment)

[duianto]

yuhan0 suggested a method for getting the latest version of undo-tree: #9903 (comment)

And it works, I just replacing the undo-tree package listing in:
+spacemacs/spacemacs-editing/packages.el

with:

(undo-tree :location (recipe
                      :fetcher git
                      :url "http://www.dr-qubit.org/git/undo-tree.git"
                      :branch "master"))

then I moved the current undo-tree-0.6.5 dir to another location (as a backup), and restarted.

Now undo-tree.el shows:

;; Version: 0.6.6
;; Package-Version: 20170706.1146

the old one showed:

;; Version: 0.6.5

and the latest changelog entry at the bottom:

;; 2013-12-28 Toby S. Cubitt tsc25@cantab.net
;;
;; * undo-tree: Update to version 0.6.5.

[agzam]

I am still having this annoying issue. Can someone publish a guide how to remove undo-tree from Spacemacs completely and maybe replace it with something that actually works.

[johnny-mh]

I have same issue.

[yyoncho]

Proposed workaround - put the following line in dotspacemacs/user-config.

  (global-undo-tree-mode -1)

This will disable undo-tree mode and it will fallback to native emacs undo-redo functionality. Source - http://ergoemacs.org/emacs/emacs_best_redo_mode.html

[practicalli-johnny]

Disabling undo-tree mode as in the message above does not resolve the problem. History is still lost, although perhaps not quite as much as with undo-tree-mode

[agzam]

This thing is utterly annoying. Can someone please suggest a workaround? Undo is one of the most important features of any editor and I it is clearly broken right now in Spacemacs. I don't understand how is it not the most pressing issue at the moment?

[agzam]

reddit discussion https://www.reddit.com/r/emacs/comments/bx82j3/somehow_my_undo_history_is_truncated_what_did_i/

[duianto]

Reproduction steps to encounter the issue: No further undo information

Copy this snippet:

(dotimes (_ 30)
  (insert "Aliquam erat volutpat.  Nunc eleifend leo vitae magna.  In id erat non orci commodo lobortis.  Proin neque massa, cursus ut, gravida ut, lobortis eget, lacus.  Sed diam.  Praesent fermentum tempor tellus.  Nullam tempus.  Mauris ac felis vel velit tristique imperdiet.  Donec at pede.  Etiam vel neque nec dui dignissim bibendum.  Vivamus id enim.  Phasellus neque orci, porta a, aliquet quis, semper a, massa.  Phasellus purus.  Pellentesque tristique imperdiet tortor.  Nam euismod tellus id erat.")
  (fill-paragraph))

• Open a new buffer SPC b N n
• Type: a (with the evil editing style return to normal state ESC)
• Open the Eval: prompt: M-:
• Paste and run the copied snippet: C-y RET
  In this state the variable: SPC h d v buffer-undo-list seems to have 16414 undo states.

(nil
 (" " . -14546)
 (14545 . 14546)
 (" " . -14466)

...

 (" " . -93)
 (" " . -55)
 (" " . -24)
 (1 . 500))

• Undo u
  the buffer only contains the initial: a
  the buffer-undo-list variable contains: (nil undo-tree-canary)
• Try to undo u again

user-error: No further undo information

Reproduced in both Ubuntu 18.04.02 and Windows 10 Version 1803.

System Info 💻

• OS: gnu/linux
• Emacs: 27.0.50
• Spacemacs: 0.300.0
• Spacemacs branch: develop (rev. 803d4e7)
• Graphic display: t
• Distribution: spacemacs
• Editing style: vim
• Completion: helm
• Layers:

(emacs-lisp git helm markdown multiple-cursors org spell-checking treemacs version-control)

• System configuration features: XPM JPEG TIFF GIF PNG RSVG SOUND GPM DBUS GSETTINGS GLIB NOTIFY INOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS XWIDGETS LIBSYSTEMD PDUMPER LCMS2 GMP

System Info 💻

• OS: windows-nt
• Emacs: 26.2
• Spacemacs: 0.300.0
• Spacemacs branch: develop (rev. 803d4e7)
• Graphic display: t
• Distribution: spacemacs
• Editing style: vim
• Completion: helm
• Layers:

(autohotkey emacs-lisp git helm javascript markdown multiple-cursors org spell-checking syntax-checking treemacs version-control)

• System configuration features: XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY ACL GNUTLS LIBXML2 ZLIB TOOLKIT_SCROLL_BARS THREADS LCMS2

[tsc25]

@duianto's comment is the first report I've seen of this widely-reported issue that includes steps to reproduce. Unfortunately, I can't reproduce with vanilla undo-tree (i.e. not using Spacemacs). Following the equivalent of @duianto's steps in vanilla Emacs+undo-tree results for me in an undo tree containing two nodes, one the empty buffer, the other the buffer with all the text inserted, as expected. Undo/redo worked perfectly.

I believe Spacemacs adds extra undo boundaries compared to vanilla Emacs (can someone confirm?). So I tried running this modified snippet:

(dotimes` (_ 30)
  (insert "Aliquam erat volutpat.  Nunc eleifend leo vitae magna.  In id erat non orci commodo lobortis.  Proin neque massa, cursus ut, gravida ut, lobortis eget, lacus.  Sed diam.  Praesent fermentum tempor tellus.  Nullam tempus.  Mauris ac felis vel velit tristique imperdiet.  Donec at pede.  Etiam vel neque nec dui dignissim bibendum.  Vivamus id enim.  Phasellus neque orci, porta a, aliquet quis, semper a, massa.  Phasellus purus.  Pellentesque tristique imperdiet tortor.  Nam euismod tellus id erat.")
(fill-paragraph)
(undo-boundary))

No luck. This produced a linear undo tree containing 31 nodes, as expected. Undo/redo still worked perfectly.

Can anyone find steps to reproduce this issue without Spacemacs? If they could, I might finally be able to make some headway with figuring out this bug! If not, it could indicate the issue is to do with how Spacemacs integrates undo-tree, rather than with the undo-tree package per se.

-- Toby (undo-tree author+maintainer)

[duianto]

When agzam posted the link to the reddit thread, that talks about that it could be a garbage collection issue. Then I messaged the spacemacs maintainers about it, and syl20bnr responded:

Lately the undo bug happens very frequently on my installations using emacs 27
pretty annoying
since spacemacs triggers GC very often it would make sense that this is the cause

[duianto]

I seem to be able to reproduce the issue without Spacemacs, by starting Emacs without any configurations and only installing undo-tree.

With the Spacemacs .emacs.d directory renamed to .emacs.d_backup.

• runemacs.exe --quick
• paste and evaluate the melpa setup:

(require 'package)
(let* ((no-ssl (and (memq system-type '(windows-nt ms-dos))
		    (not (gnutls-available-p))))
       (proto (if no-ssl "http" "https")))
  ;; Comment/uncomment these two lines to enable/disable MELPA and MELPA Stable as desired
  (add-to-list 'package-archives (cons "melpa" (concat proto "://melpa.org/packages/")) t)
  ;;(add-to-list 'package-archives (cons "melpa-stable" (concat proto "://stable.melpa.org/packages/")) t)
  (when (< emacs-major-version 24)
    ;; For important compatibility libraries like cl-lib
    (add-to-list 'package-archives '("gnu" . (concat proto "://elpa.gnu.org/packages/")))))
(package-initialize)

• M-x eval-buffer
• M-x package-install undo-tree RET
• C-x b test RET`
• M-x undo-tree-mode RET
  checking C-h v buffer-undo-list RET shows that it's nil
• Type: a
• Copy this snippet to the clipboard:

(dotimes (_ 30)
  (insert "Aliquam erat volutpat.  Nunc eleifend leo vitae magna.  In id erat non orci commodo lobortis.  Proin neque massa, cursus ut, gravida ut, lobortis eget, lacus.  Sed diam.  Praesent fermentum tempor tellus.  Nullam tempus.  Mauris ac felis vel velit tristique imperdiet.  Donec at pede.  Etiam vel neque nec dui dignissim bibendum.  Vivamus id enim.  Phasellus neque orci, porta a, aliquet quis, semper a, massa.  Phasellus purus.  Pellentesque tristique imperdiet tortor.  Nam euismod tellus id erat.")
  (fill-paragraph))

• Open the Eval: prompt: M-:
• Paste and run the snippet: C-y RET
  checking the variable again: C-h v M-p (select the previous minibuffer history item) RET
  switch to the help buffer C-x o, searching for C-s value: shows:

Value:
(nil
 (" " . -14883)
 (14882 . 14883)
 (" " . -14818)

...

switching back to the test buffer C-x o

• M-x undo-tree-undo RET
  only a is left in the buffer, undo-buffer-list shows the value as nil.
• M-x undo-tree-undo RET
  The messages buffer shows:

user-error: No further undo information

System info

GNU Emacs 26.2 (build 1, x86_64-w64-mingw32) of 2019-04-13
Windows 10 Version 1803 (OS Build 17134.829)

Also reproduced with:
GNU Emacs 27.0.50 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.22.30) of 2019-06-09
Ubuntu 18.04.2 LTS