bug#39793: 28.0.50; set-file-modes nofollow does not work on mounted directories

[Michael Albinus]

Using recent master.

I have my ~/.nnmail-cache file on a mounted directory:

--8<---------------cut here---------------start------------->8---
# ls -l ~/.nnmail-cache
lrwxrwxrwx 1 albinus albinus 31 Mar 12  2012 /home/albinus/.nnmail-cache -> 
/net/ford/albinus/.nnmail-cache
--8<---------------cut here---------------end--------------->8---

This prevents me from reding new mails via gnus:

--8<---------------cut here---------------start------------->8---
Debugger entered--Lisp error: (file-error "Doing chmod" "Operation not 
supported" "/home/albinus/.nnmail-cache")
  set-file-modes("~/.nnmail-cache" 384 nofollow)
  nnmail-write-region(1 1891048 "~/.nnmail-cache" nil silent)
  nnmail-cache-close()
  nnmail-get-new-mail-1(nnml nnml-save-incremental-nov "~/Mail" nil nil nil)
  nnmail-get-new-mail(nnml nnml-save-incremental-nov "~/Mail" nil)
  nnml-request-scan(nil "")
  gnus-request-scan(nil (nnml ""))
  gnus-read-active-file-1((nnml "") nil)
  gnus-read-active-for-groups((nnml "") (("nnml:zumbusch" 3 ((1 . 13)) 
((unexist) (seen ...) (reply 7 12)) "nnml:" ((timestamp 22158 47874))) 
("nnml:yahoo" 3 ((1 . 5)) nil "nnml:") ("nnml:wenzel" 3 ((1 . 96)) ((unexist) 
(seen ... ... ... 80 82 84 ... 89 ...) (forward 68 78) (reply 1 58 ... 68 71 
... 78 80 82 84 87 89 93 96)) "nnml:" ((timestamp . 1575130099))) 
("nnml:vodafone" 3 ((1 . 1)) ((unexist) (seen 1)) "nnml:" ((timestamp 23430 
52917))) ("nnml:vio" 3 ((1 . 5)) ((reply 4) (unexist) (seen 1)) "nnml:" 
((timestamp 22786 64120))) ("nnml:verein" 3 ((1 . 51)) ((seen ...) (forward 47 
51) (reply 47 49)) "nnml:" ((timestamp 19980 58085))) ("nnml:tramp-archive" 3 
((1 . 11506)) ((unexist) (seen ...) (forward 8365 8621 8994 9285 9686 10101 
10441 10619) (reply 7750 7763 7766 ... 7809 7812 7844 7846 7848 7852 7855 7891 
7893 7901 7904 7913 7915 7921 7923 7925 7937 7939 7942 7944 7954 7965 7977 7980 
7982 7984 7986 ...) (tick ... 6904 8007 ... 8084)) "nnml:" ((timestamp . 
1561491236))) ("nnml:tramp" 3 ((1 . 12332) (12334 . 12336) 12338 (12341 . 
12342) (12344 . 12615) (12617 . 13112) (13114 . 13687) (13689 . 14816) (14818 . 
14862) (14864 . 15327) (15329 . 15633) (15635 . 18133) (18135 . 18886) (18888 . 
18889) (18891 . 18923) (19110 . 19113)) ((unexist) (seen ... ...) (forward 9654 
9985 11619 11980 12431 12667 13152 13698 14092 14545 14954 ... 14975 15050 
15575 16060 16140 16674 16677 17568 17795 18235 18456) (reply 9644 9646 9651 
9663 9667 9680 ... 9685 9693 9696 9701 ... 9710 ... 9716 9730 9732 9734 9736 
9741 9750 9752 9761 9764 9766 ... 9774 ... 9786 9789 9793 ...) (tick 11692 
11702)) "nnml:" ((timestamp . 1578399220))) ("nnml:tieto" 3 ((1 . 21)) ((seen 
...) (save 9 18) (reply 3 ... ... 16)) "nnml:" ((timestamp 19906 58758))) 
("nnml:threads" 3 ((1 . 167) (173 . 175) (177 . 179) (190 . 193) (195 . 273) 
(281 . 324)) ((unexist) (seen ... 288) (reply 155 199 201 203 ... ... 229 231 
233 ... 238 240 248 256 262 269 298)) "nnml:" ((timestamp . 1578398332))) 
("nnml:thiel" 3 ((1 . 1)) ((unexist) (seen 1)) "nnml:" ((timestamp 22996 
44872))) ("nnml:telekom" 3 ((1 . 88)) nil "nnml:") ("nnml:susann" 3 ((1 . 651)) 
((unexist) (seen ... ...) (forward 410 413 432 447 469 499 503 ... 522 531 544 
546 594 613 632 644) (save 412 499) (reply 348 368 377 379 381 387 389 394 ... 
420 426 428 443 468 471 473 486 488 491 498 501 ... 508 512 518 524 531 536 546 
548 ... ...)) "nnml:" ((timestamp . 1567012544))) ("nnml:spezis" 3 ((1 . 53)) 
((seen ...) (reply 34 36 40 ... 51 53)) "nnml:" ((timestamp 21049 31758))) 
("nnml:sonos" 3 ((1 . 9)) nil "nnml:") ("nnml:sigrid" 3 ((1 . 978) 995) 
((unexist) (seen ... ...) (forward ... 410 ... 431 ... 444 ... 475 ... ... 503 
508 514 517 528 ... ... ... 593 595 ... 603 ... 617 620 ... 668 679 687 690 705 
...) (save 362 367 397 569 ...) (reply 363 368 412 420 434 458 465 467 484 ... 
... 503 508 514 540 542 549 552 ... 564 566 569 579 586 590 597 610 632 643 645 
648 ...)) "nnml:" ((timestamp . 1574345954))) ("nnml:shanmug" 3 ((1 . 5)) nil 
"nnml:") ("nnml:seminartreffen" 3 ((1 . 4)) nil "nnml:") ("nnml:rms" 3 ((1 . 
5)) ((seen ...)) "nnml:" ((timestamp 19806 62525))) ("nnml:ristock" 3 ((1 . 
20)) nil "nnml:") ("nnml:rimbach" 3 ((1 . 1)) nil "nnml:") ("nnml:ralf" 3 ((1 . 
14)) ((unexist) (seen ...)) "nnml:" ((timestamp 22623 44813))) ("nnml:rainer" 3 
((1 . 11)) ((unexist) (seen ...) (forward ...) (save 2) (reply 2 8 11)) "nnml:" 
((timestamp 23645 26101))) ("nnml:pospiech" 3 ((1 . 4)) nil "nnml:") 
("nnml:pierru" 3 ((1 . 107)) ((unexist) (seen ...) (forward 88 101 103) (reply 
88 90 93 95 98 ... 106)) "nnml:" ((timestamp . 1577728372))) ("nnml:pieplow" 3 
((1 . 5)) ((unexist) (seen ...)) "nnml:" ((timestamp 21534 22076))) ("nnml:pgp" 
3 ((1 . 4)) nil "nnml:") ("nnml:paypal" 3 ((1 . 222)) ((unexist) (seen ...) 
(forward 56 60 108 116 180 ... 207 210)) "nnml:" ((timestamp . 1577353063))) 
("nnml:paschelke" 3 ((1 . 3)) nil "nnml:") ("nnml:own-messages" 3 ((1 . 201)) 
((unexist) (seen ...) (forward ... 80 98 149) (reply 77 ... 93 106 109 111 ... 
...)) "nnml:" ((timestamp . 1577435097))) ("nnml:mueller" 3 ((1 . 4)) nil 
"nnml:") ("nnml:moeller" 3 ((1 . 3)) nil "nnml:") ...) nil)
  gnus-get-unread-articles(nil nil nil)
  gnus-group-get-new-news(nil)
  funcall-interactively(gnus-group-get-new-news nil)
  call-interactively(gnus-group-get-new-news nil nil)
  command-execute(gnus-group-get-new-news)
--8<---------------cut here---------------end--------------->8---

Best regards, Michael.


In GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.12, cairo 
version 1.16.0)
 of 2020-02-25 built on detlef
Repository revision: 64af3c94a6197cd0c6a283880c900eeb5bf12961
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12005000
System Description: Ubuntu 19.10

Recent messages:
Reading active file via nnnil...done
Reading active file from news via nntp...
Opening nntp server on news...done
Reading active file via nnml...
Reading incoming mail from pop...
pop3 retrieved 0KB (0%) [6 times]
pop3 retrieved 6KB (100%)
Wrote /home/albinus/Mail/default/28870
nnml: Reading incoming mail (1 new)...done
Entering debugger...

Configured features:
XPM JPEG TIFF GIF PNG RSVG CAIRO SOUND GPM DBUS GSETTINGS GLIB NOTIFY
INOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE HARFBUZZ M17N_FLT LIBOTF
ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS PDUMPER LCMS2
GMP

Important settings:
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=none
  locale-coding-system: utf-8

Major mode: Debugger

Minor modes in effect:
  erc-notify-mode: t
  erc-notifications-mode: t
  display-time-mode: t
  shell-dirtrack-mode: t
  delete-selection-mode: t
  icomplete-mode: t
  show-paren-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
/home/albinus/src/elpa/packages/debbugs/debbugs-org hides 
/home/albinus/.emacs.d/elpa/debbugs-0.22/debbugs-org
/home/albinus/src/elpa/packages/debbugs/debbugs-gnu hides 
/home/albinus/.emacs.d/elpa/debbugs-0.22/debbugs-gnu
/home/albinus/src/elpa/packages/debbugs/debbugs hides 
/home/albinus/.emacs.d/elpa/debbugs-0.22/debbugs
/home/albinus/src/elpa/packages/debbugs/debbugs-autoloads hides 
/home/albinus/.emacs.d/elpa/debbugs-0.22/debbugs-autoloads
/home/albinus/src/elpa/packages/debbugs/debbugs-pkg hides 
/home/albinus/.emacs.d/elpa/debbugs-0.22/debbugs-pkg
/home/albinus/src/elpa/packages/debbugs/debbugs-browse hides 
/home/albinus/.emacs.d/elpa/debbugs-0.22/debbugs-browse
~/lisp/telepathy hides 
/home/albinus/.emacs.d/elpa/telepathy-20131209.1258/telepathy
/home/albinus/src/elpa/packages/tramp-theme/tramp-theme hides 
/home/albinus/.emacs.d/elpa/tramp-theme-0.2/tramp-theme
/home/albinus/src/elpa/packages/tramp-theme/tramp-theme-autoloads hides 
/home/albinus/.emacs.d/elpa/tramp-theme-0.2/tramp-theme-autoloads
/home/albinus/src/elpa/packages/tramp-theme/tramp-theme-pkg hides 
/home/albinus/.emacs.d/elpa/tramp-theme-0.2/tramp-theme-pkg
/home/albinus/src/tramp/lisp/tramp-smb hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-smb
/home/albinus/src/tramp/lisp/tramp-sudoedit hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-sudoedit
/home/albinus/src/tramp/lisp/tramp-uu hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-uu
/home/albinus/src/tramp/lisp/tramp-adb hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-adb
/home/albinus/src/tramp/lisp/tramp-compat hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-compat
/home/albinus/src/tramp/lisp/tramp-integration hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-integration
/home/albinus/src/tramp/lisp/tramp-archive hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-archive
/home/albinus/src/tramp/lisp/tramp hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp
/home/albinus/src/tramp/lisp/trampver hides 
/usr/local/share/emacs/28.0.50/lisp/net/trampver
/home/albinus/src/tramp/lisp/tramp-rclone hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-rclone
/home/albinus/src/tramp/lisp/tramp-ftp hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-ftp
/home/albinus/src/tramp/lisp/tramp-cmds hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-cmds
/home/albinus/src/tramp/lisp/tramp-gvfs hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-gvfs
/home/albinus/src/tramp/lisp/tramp-loaddefs hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-loaddefs
~/lisp/dbus hides /usr/local/share/emacs/28.0.50/lisp/net/dbus
/home/albinus/src/tramp/lisp/tramp-sh hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-sh
/home/albinus/src/tramp/lisp/tramp-cache hides 
/usr/local/share/emacs/28.0.50/lisp/net/tramp-cache

Features:
(shadow warnings emacsbug help-fns radix-tree cl-print debug backtrace
find-func mailalias sort gnus-cite mail-extr nnir cl-extra help-mode qp
gnus-ml pop3 utf-7 nndraft nnmh nnml gnus-agent gnus-srvr gnus-score
score-mode nnvirtual gnus-msg gnus-art mm-uu mml2015 mm-view mml-smime
smime dig gnus-cache gnus-sum shr svg dom nnnil smtpmail sendmail
gnus-demon nntp gnus-group gnus-undo gnus-start gnus-cloud nnimap nnmail
mail-source utf7 netrc nnoo gnus-spec gnus-int gnus-range message rfc822
mml mml-sec epa epg epg-config mm-decode mm-bodies mm-encode mailabbrev
gmm-utils mailheader gnus-win gnus nnheader gnus-util rmail
rmail-loaddefs text-property-search wid-edit cus-start cus-load vc
vc-dispatcher erc-notify erc-networks erc-desktop-notifications
erc-match notifications dbus xml erc-goodies erc erc-backend erc-compat
thingatpt pp erc-loaddefs cperl-mode emba derived mail-utils
network-stream url-cache glab ghub-graphql treepy gsexp ghub url-http
mail-parse rfc2231 rfc2047 rfc2045 mm-util ietf-drums mail-prsvr url-gw
nsm rmc url-auth url url-proxy url-privacy url-expand url-methods
url-history url-cookie url-domsuf url-util mailcap let-alist gnutls puny
time tramp-sh kubernetes-tramp lxc-tramp lxd-tramp docker-tramp
tramp-cache vagrant-tramp dash term disp-table ehelp tramp
tramp-loaddefs trampver tramp-integration files-x tramp-compat shell
pcomplete comint ansi-color ring parse-time iso8601 time-date ls-lisp
format-spec delsel ido jka-compr icomplete paren dired dired-loaddefs
edmacro kmacro slime-autoloads info package easymenu browse-url
url-handlers url-parse auth-source cl-seq eieio eieio-core cl-macs
eieio-loaddefs password-cache json subr-x map url-vars seq byte-opt gv
bytecomp byte-compile cconv cl-loaddefs cl-lib tooltip eldoc electric
uniquify ediff-hook vc-hooks lisp-float-type mwheel term/x-win x-win
term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page tab-bar menu-bar rfn-eshadow isearch timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame minibuffer cl-generic cham georgian utf-8-lang
misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms
cp51932 hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese composite charscript charprop case-table epa-hook
jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote threads dbusbind inotify lcms2 dynamic-setting
system-font-setting font-render-setting cairo move-toolbar gtk x-toolkit
x multi-tty make-network-process emacs)

Memory information:
((conses 16 271174 20205)
 (symbols 48 24771 1)
 (strings 32 81567 5419)
 (string-bytes 1 2848631)
 (vectors 16 34442)
 (vector-slots 8 449623 29076)
 (floats 8 243 105)
 (intervals 56 2511 0)
 (buffers 1000 33))