bug#40766: 27.0.91; Cannot edebug cl-lambda-list edebug spec

bug#40766: 27.0.91; Cannot edebug cl-lambda-list edebug spec

[Philipp Stephani]

emacs -Q
M-x find-library RET cl-macs RET
Navigate to the form `(def-edebug-spec cl-lambda-list ...)'
Hit C-u C-M-x to edebug it.

This results in an error with backtrace:

Debugger entered--Lisp error: (invalid-read-syntax "Expected one of" "nil" edebug-spec-p "t" "0" (&rest edebug-spec))
  signal(invalid-read-syntax ("Expected one of" "nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
  edebug-syntax-error("Expected one of" "nil" edebug-spec-p "t" "0" (&rest edebug-spec))
  apply(edebug-syntax-error ("Expected one of" "nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
  edebug-no-match((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) "Expected one of" "nil" edebug-spec-p "t" "0" (&rest edebug-spec))
  apply(edebug-no-match (((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) "Expected one of" ("nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
  edebug-match-&or((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) ("nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
  edebug-match-specs((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) (&or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)) edebug-match-specs)
  edebug-match-specs((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) (name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)) edebug-match-specs)
  edebug-match-specs((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) (:name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)) edebug-match-specs)
  edebug-match-specs((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) ("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)) edebug-match-specs)
  edebug-match-sublist((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) ("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
  edebug-match-list((((def-edebug-spec cl-lambda-list (([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" ... &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or ... symbolp]] . [&or arg nil])))) (6563 (6564 . 6579) (6580 . 6594) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 ... ... ... . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 ... ... ... . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916)) ("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
  edebug-match-one-spec((((def-edebug-spec cl-lambda-list (([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" ... &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or ... symbolp]] . [&or arg nil])))) (6563 (6564 . 6579) (6580 . 6594) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 ... ... ... . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 ... ... ... . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916)) ("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
  edebug-match-specs((((def-edebug-spec cl-lambda-list (([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" ... &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or ... symbolp]] . [&or arg nil])))) (6563 (6564 . 6579) (6580 . 6594) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 ... ... ... . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 ... ... ... . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916)) (("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec))) edebug-match-specs)
  edebug-match((((def-edebug-spec cl-lambda-list (([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" ... &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or ... symbolp]] . [&or arg nil])))) (6563 (6564 . 6579) (6580 . 6594) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 ... ... ... . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 ... ... ... . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916)) (("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec))))
  edebug-make-form-wrapper((((def-edebug-spec cl-lambda-list (([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" ... &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or ... symbolp]] . [&or arg nil])))) (6563 (6564 . 6579) (6580 . 6594) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 ... ... ... . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 ... ... ... . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916)) 6563 6915 (("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec))))
  edebug-read-and-maybe-wrap-form1()
  edebug-read-and-maybe-wrap-form()
  edebug-read-top-level-form()
  edebug-eval-defun((4))
  apply(edebug-eval-defun (4))
  eval-defun((4))
  funcall-interactively(eval-defun (4))
  call-interactively(eval-defun nil nil)
  command-execute(eval-defun)



In GNU Emacs 27.0.91 (build 3, x86_64-pc-linux-gnu, GTK+ Version 3.24.13)
 of 2020-04-20
Repository revision: a1040861f118881004f59866111f64cd0ae03b7a
Repository branch: emacs-27
Windowing system distributor 'The X.Org Foundation', version 11.0.12004000
System Description: Debian GNU/Linux rodete

Recent messages:
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Configured using:
 'configure --enable-checking=all --enable-gtk-deprecation-warnings
 --enable-gcc-warnings=warn-only --enable-check-lisp-object-type
 --with-mailutils --without-pop 'CFLAGS=-O0 -g3' LDFLAGS=-g3'

Configured features:
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LIBSELINUX GNUTLS FREETYPE HARFBUZZ XFT ZLIB TOOLKIT_SCROLL_BARS GTK3
X11 XDBE XIM MODULES THREADS PDUMPER GMP

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  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
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Load-path shadows:
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Memory information:
((conses 16 63376 5964)
 (symbols 48 8446 1)
 (strings 32 22409 1771)
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 (vectors 16 12506)
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bug#40766: 27.0.91; Cannot edebug cl-lambda-list edebug spec

[Alan Mackenzie]

Hello, Philipp.

In article <mailman.944.1587560406.3066.bug-gnu-emacs@gnu.org> you wrote:

> emacs -Q
> M-x find-library RET cl-macs RET
> Navigate to the form `(def-edebug-spec cl-lambda-list ...)'
> Hit C-u C-M-x to edebug it.

> This results in an error with backtrace:

Yes, I get this too.  The debug-spec definition looks like this:

    (def-edebug-spec cl-lambda-list
      (([&rest cl-lambda-arg]
        [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]]
        [&optional ["&rest" cl-lambda-arg]]
        [&optional ["&key" [cl-&key-arg &rest cl-&key-arg]
                    &optional "&allow-other-keys"]]
        [&optional ["&aux" &rest
                    &or (symbolp &optional def-form) symbolp]]
        . [&or arg nil])))

After playing around with it for a few hours, it is clear that the
bug is triggered by a combination of (i) the dot on the last line; and
(ii) the presence of at least one [&optional ...] before it, at the same
level of nesting.  Possibly the nesting of [ ... ] structures might have
something to do with it.

The debug-spec which we are attempting to use to parse the above is that
of deb-edebug-spec itself.  Let's call this "spec 2".

There is a dynamically bound variable edebug-dotted-spec which gets bound
to t when the parser encounters a "dotted spec" in spec 2.  The criterion
for making this binding is that the current fragment of spec 2,
presumably the last cdr in a list is a non-nil atom.  A vector is also an
atom, and it might be that there is confusion about this in edebug.el.
I'm still working on it.

Just one other comment.  Doing C-u C-M-x on an edebug-spec doesn't seem
to lead to any entry into edebug, even when this bug doesn't trigger.

Thanks for an interesting bug!

> Debugger entered--Lisp error: (invalid-read-syntax "Expected one of" "nil" edebug-spec-p "t" "0" (&rest edebug-spec))
>   signal(invalid-read-syntax ("Expected one of" "nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
>   edebug-syntax-error("Expected one of" "nil" edebug-spec-p "t" "0" (&rest edebug-spec))
>   apply(edebug-syntax-error ("Expected one of" "nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
>   edebug-no-match((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) "Expected one of" "nil" edebug-spec-p "t" "0" (&rest edebug-spec))
>   apply(edebug-no-match (((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) "Expected one of" ("nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
>   edebug-match-&or((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) ("nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
>   edebug-match-specs((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) (&or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)) edebug-match-specs)
>   edebug-match-specs((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) (name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)) edebug-match-specs)
>   edebug-match-specs((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) (:name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)) edebug-match-specs)
>   edebug-match-specs((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) ("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)) edebug-match-specs)
>   edebug-match-sublist((((([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" [cl-&key-arg &rest cl-&key-arg] &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or (symbolp &optional def-form) symbolp]] . [&or arg nil]))) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 (6755 . 6766) (6767 . 6772) (6773 . 6784) . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 (6856 . 6863) (6864 . 6873) (6874 . 6882) . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916) ("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
>   edebug-match-list((((def-edebug-spec cl-lambda-list (([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" ... &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or ... symbolp]] . [&or arg nil])))) (6563 (6564 . 6579) (6580 . 6594) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 ... ... ... . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 ... ... ... . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916)) ("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
>   edebug-match-one-spec((((def-edebug-spec cl-lambda-list (([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" ... &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or ... symbolp]] . [&or arg nil])))) (6563 (6564 . 6579) (6580 . 6594) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 ... ... ... . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 ... ... ... . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916)) ("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec)))
>   edebug-match-specs((((def-edebug-spec cl-lambda-list (([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" ... &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or ... symbolp]] . [&or arg nil])))) (6563 (6564 . 6579) (6580 . 6594) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 ... ... ... . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 ... ... ... . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916)) (("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec))) edebug-match-specs)
>   edebug-match((((def-edebug-spec cl-lambda-list (([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" ... &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or ... symbolp]] . [&or arg nil])))) (6563 (6564 . 6579) (6580 . 6594) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 ... ... ... . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 ... ... ... . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916)) (("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec))))
>   edebug-make-form-wrapper((((def-edebug-spec cl-lambda-list (([&rest cl-lambda-arg] [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]] [&optional ["&rest" cl-lambda-arg]] [&optional ["&key" ... &optional "&allow-other-keys"]] [&optional ["&aux" &rest &or ... symbolp]] . [&or arg nil])))) (6563 (6564 . 6579) (6580 . 6594) (6597 (6598 (6599 (6600 . 6605) (6606 . 6619) . 6620) (6625 (6626 . 6635) (6636 (6637 . 6648) (6649 . 6665) (6666 . 6671) (6672 . 6688) . 6689) . 6690) (6695 (6696 . 6705) (6706 (6707 . 6714) (6715 . 6728) . 6729) . 6730) (6735 (6736 . 6745) (6746 (6747 . 6753) (6754 ... ... ... . 6785) (6788 . 6797) (6798 . 6817) . 6818) . 6819) (6824 (6825 . 6834) (6835 (6836 . 6842) (6843 . 6848) (6851 . 6854) (6855 ... ... ... . 6883) (6884 . 6891) . 6892) . 6893) (6899 (6901 . 6904) (6905 . 6908) (6909 . 6912) . 6913) . 6914) . 6915) . 6916)) 6563 6915 (("def-edebug-spec" :name edebug-spec name &or "nil" edebug-spec-p "t" "0" (&rest edebug-spec))))
>   edebug-read-and-maybe-wrap-form1()
>   edebug-read-and-maybe-wrap-form()
>   edebug-read-top-level-form()
>   edebug-eval-defun((4))
>   apply(edebug-eval-defun (4))
>   eval-defun((4))
>   funcall-interactively(eval-defun (4))
>   call-interactively(eval-defun nil nil)
>   command-execute(eval-defun)



> In GNU Emacs 27.0.91 (build 3, x86_64-pc-linux-gnu, GTK+ Version 3.24.13)
>  of 2020-04-20
> Repository revision: a1040861f118881004f59866111f64cd0ae03b7a
> Repository branch: emacs-27
> Windowing system distributor 'The X.Org Foundation', version 11.0.12004000
> System Description: Debian GNU/Linux rodete

[ .... ]

> -- 
> Google Germany GmbH
> Erika-Mann-Straße 33
> 80636 München

-- 
Alan Mackenzie (Nuremberg, Germany).

bug#40766: 27.0.91; Cannot edebug cl-lambda-list edebug spec

[Alan Mackenzie]

Hello again, Philipp.

On Thu, Apr 23, 2020 at 06:41:28 -0000, Alan Mackenzie wrote:
> In article <mailman.944.1587560406.3066.bug-gnu-emacs@gnu.org> you wrote:

> > emacs -Q
> > M-x find-library RET cl-macs RET
> > Navigate to the form `(def-edebug-spec cl-lambda-list ...)'
> > Hit C-u C-M-x to edebug it.

> > This results in an error with backtrace:

Yes.  There is a bug in the edebug specs for edebug-spec-list and
edebug-spec.  (Sorry about this sounding confusing.  Believe me, it's
nothing compared with the head banging involved in keeping various
levels of the debug specs mentally separate.  ;-)  These two specs are
the main components of the debug spec for def-edebug-spec.  (It's
probably still confusing at this stage.)  These two things look like
this:

    (def-edebug-spec edebug-spec-list
      ;; A list must have something in it, or it is nil, a symbolp
      ((edebug-spec . [&or nil edebug-spec])))

    (def-edebug-spec edebug-spec
      (&or
    ; edebug-spec-list   <==============================================
       (vector &rest edebug-spec)           ; matches a vector
       ("vector" &rest edebug-spec)         ; matches a vector spec
       ("quote" symbolp)
       edebug-spec-list ;; <============================================
       stringp
       [edebug-lambda-list-keywordp &rest edebug-spec]
       [keywordp gate edebug-spec]
       edebug-spec-p  ;; Including all the special ones e.g. form.
       symbolp;; a predicate
       ))

The target spec, let's continue calling it spec 2, reduced to it's
minimum required to trigger the bug, looks like:

    (def-edebug-spec acm-lambda-list
      (([&rest cl-lambda-arg]
        ["&optional" cl-&optional-arg &rest cl-&optional-arg]
        . [&or arg nil])))

.  The essential attributes are it has enclosing parens (at least)
containing two vectors followed by a dot followed by a third vector.

When spec 2 gets parsed by edebug-spec (see above), it eventually
reaches a dotted list containing the three vectors.  It parses this with
edebug-spec-list containing the first two vectors.  But BECAUSE
edebug-spec-list IS MISPLACED INSIDE edebug-spec (see the two arrowed
lines), the second vector triggers recognition by (vector ....) rather
than by edebug-spec-list.  This "dedottifies" the dotted list in spec 2,
so that when the dot in spec 2 is reached, edebug-spec-list doesn't know
how to handle it.  For some reason, the backtracking doesn't backtrack
here.

The solution to the problem is to move the edebug-spec-list from after
the (vector ...) and ("quote" ....) entries to before them, as indicated
above.  This causes the second vector to get handled as the first
element of the cdr of the list it's contained within.


> Yes, I get this too.  The debug-spec definition looks like this:

>     (def-edebug-spec cl-lambda-list
>       (([&rest cl-lambda-arg]
>         [&optional ["&optional" cl-&optional-arg &rest cl-&optional-arg]]
>         [&optional ["&rest" cl-lambda-arg]]
>         [&optional ["&key" [cl-&key-arg &rest cl-&key-arg]
>                     &optional "&allow-other-keys"]]
>         [&optional ["&aux" &rest
>                     &or (symbolp &optional def-form) symbolp]]
>         . [&or arg nil])))

> After playing around with it for a few hours, it is clear that the
> bug is triggered by a combination of (i) the dot on the last line; and
> (ii) the presence of at least one [&optional ...] before it, at the same
> level of nesting.  Possibly the nesting of [ ... ] structures might have
> something to do with it.

So, I propose installing the following patch to fix the bug:


diff --git a/lisp/emacs-lisp/edebug.el b/lisp/emacs-lisp/edebug.el
index bb7817f242..7995a9e5a2 100644
--- a/lisp/emacs-lisp/edebug.el
+++ b/lisp/emacs-lisp/edebug.el
@@ -2115,10 +2115,10 @@ edebug-spec-list
 
 (def-edebug-spec edebug-spec
   (&or
+   edebug-spec-list
    (vector &rest edebug-spec)		; matches a vector
    ("vector" &rest edebug-spec)		; matches a vector spec
    ("quote" symbolp)
-   edebug-spec-list
    stringp
    [edebug-lambda-list-keywordp &rest edebug-spec]
    [keywordp gate edebug-spec]


> > -- 
> > Google Germany GmbH
> > Erika-Mann-Straße 33
> > 80636 München

-- 
Alan Mackenzie (Nuremberg, Germany).

bug#40766: 27.0.91; Cannot edebug cl-lambda-list edebug spec

[Alan Mackenzie]

Hello, Philipp.

On Thu, Apr 23, 2020 at 06:41:28 -0000, Alan Mackenzie wrote:

> In article <mailman.944.1587560406.3066.bug-gnu-emacs@gnu.org> you wrote:

> > emacs -Q
> > M-x find-library RET cl-macs RET
> > Navigate to the form `(def-edebug-spec cl-lambda-list ...)'
> > Hit C-u C-M-x to edebug it.

> > This results in an error with backtrace:

The bug has been fixed in the Emacs master branch.

> > -- 
> > Google Germany GmbH
> > Erika-Mann-Straße 33
> > 80636 München

-- 
Alan Mackenzie (Nuremberg, Germany).

bug#40766: 27.0.91; Cannot edebug cl-lambda-list edebug spec

[Philipp Stephani]

Am Fr., 24. Apr. 2020 um 18:01 Uhr schrieb Alan Mackenzie <acm@muc.de>:
>
> Hello, Philipp.
>
> On Thu, Apr 23, 2020 at 06:41:28 -0000, Alan Mackenzie wrote:
>
> > In article <mailman.944.1587560406.3066.bug-gnu-emacs@gnu.org> you wrote:
>
> > > emacs -Q
> > > M-x find-library RET cl-macs RET
> > > Navigate to the form `(def-edebug-spec cl-lambda-list ...)'
> > > Hit C-u C-M-x to edebug it.
>
> > > This results in an error with backtrace:
>
> The bug has been fixed in the Emacs master branch.

Thanks a lot for tracking this down and fixing it so quickly!