Subject: 28.0.50; Tramp hangs with bad prompt even when using /bin/sh

From: Erik Hetzner <[email-masked]>
Date: Fri, 12 Feb 2021 10:14:49 -0800

Hello,

1. Create a new user: `adduser test`
2. `sudo su test` and ensure that home directory is completely empty
3. `echo PS1=badprompt > .bash_profile
4. Switch back to main user
5. Start emacs with emacs -q
6. C-x C-f /ssh:test@localhost:

Expected result: dired for test user home dir.

Actual result: tramp hangs.

This kind of issue is well documented on the internet (stackexchange,
etc.) but I haven't seen a bug for it.

As I understand it, because `tramp-default-remote-shell' is set to
/bin/sh, tramp should ignore `.bash_profile`. When I look at running
shells, all I see is /bin/sh, so it's not clear to me where/why/how
/bin/bash is being invoked.

Thank you!

best, Erik Hetzner

In GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.20, cairo version 1.16.0)
 of 2021-02-10 built on lcy01-amd64-026
Repository revision: 4fba79feee58e074d112bb47467913f9aec089c7
Repository branch: feature/native-comp
Windowing system distributor 'The X.Org Foundation', version 11.0.12009000
System Description: Ubuntu 20.04.2 LTS

Configured using:
 'configure --prefix=/snap/emacs/current/usr --with-x-toolkit=gtk3
 --without-xaw3d --with-modules --with-cairo --with-nativecomp
 'CFLAGS=-isystem/build/emacs/parts/emacs/install/usr/include
 -isystem/build/emacs/parts/emacs/install/usr/include/x86_64-linux-gnu
 -O2' 'CPPFLAGS=-isystem/build/emacs/parts/emacs/install/usr/include
 -isystem/build/emacs/parts/emacs/install/usr/include/x86_64-linux-gnu'
 'LDFLAGS=-L/build/emacs/parts/emacs/install/lib
 -L/build/emacs/parts/emacs/install/usr/lib
 -L/build/emacs/parts/emacs/install/lib/x86_64-linux-gnu
 -L/build/emacs/parts/emacs/install/usr/lib/x86_64-linux-gnu''

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

Important settings:
  value of $LC_MONETARY: en_US.UTF-8
  value of $LC_NUMERIC: en_US.UTF-8
  value of $LC_TIME: en_US.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  shell-dirtrack-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-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
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs
rfc822 mml mml-sec epa derived epg epg-config gnus-util rmail
rmail-loaddefs text-property-search mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils cl-print tramp-adb
tramp-archive tramp-ftp tramp-gvfs zeroconf url-util url-parse url-vars
dbus xml thingatpt help-fns radix-tree help-mode easymenu tramp-cmds
tramp-cache tramp-sh 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 auth-source cl-seq eieio
eieio-core cl-macs eieio-loaddefs cl-loaddefs cl-lib password-cache json
subr-x map seq byte-opt gv bytecomp byte-compile cconv iso-transl
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 button loaddefs faces cus-face pcase macroexp files
window 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
nativecomp emacs)

Memory information:
((conses 16 104276 7827)
 (symbols 48 9051 0)
 (strings 32 31208 3140)
 (string-bytes 1 1013359)
 (vectors 16 16649)
 (vector-slots 8 350770 9051)
 (floats 8 37 235)
 (intervals 56 362 0)
 (buffers 984 13))