bug#42836: 27.1; default-directory is set to "/" after startup

[Sean Devlin <spd@toadstyle.org>]

Hi folks,

When I start Emacs, the value of default-directory in the *scratch* and
*Messages* buffers is "/". In previous versions of Emacs, it was "~/".

I am on macOS, and I installed Emacs 27.1 as packaged by
https://emacsformacosx.com. There is information about how this is built
and packaged here: https://emacsformacosx.com/about.

Basically, it provides a .app bundle as per typical on macOS. This lets
you open Emacs by clicking on the application icon or running "open -a
Emacs" from the terminal. You can also run it directly by invoking the
full path to the executable
(e.g. /Applications/Emacs.app/Contents/MacOS/Emacs) from the terminal.

When I open Emacs 27.1 by either of the first two methods, the value of
default-directory in the *scratch* and *Messages* buffers is "/". This
is true even though the process working directory is my home directory,
which I verified by running "lsof -a -d cwd -p $(pgrep -i emacs)" after
starting Emacs.

I reinstalled a copy of Emacs 26.3 and verified default-directory used
to be "~/" in these buffers after startup.

When I open Emacs 27.1 by invoking the executable directly (i.e. the
last method above), the default-directory in those buffers is "~/".

I have performed all the above steps using the "-Q" argument to make
sure my own configuration is not confounding anything.

I think you should be able to reproduce by the following steps:

1. Download Emacs from https://emacsformacosx.com and install the
application. (I think
https://emacsformacosx.com/emacs-builds/Emacs-27.1-universal.dmg is the
right URL.)
2. In a terminal, run "open -a Emacs --args -Q" to start Emacs.
3. Once Emacs starts, switch to the *scratch* buffer and evaluate
"default-directory" or "(pwd)" and observe the result.

I tried to do a little digging to determine how and when this variable
is first set to "/", but I couldn't figure it out. It seems that the
default directory is already "/" by the time early-init.el runs. I
determined this by putting "(message default-directory)" in my
early-init.el file and checking the messages buffer after startup.

Please let me know if there's any more information I can provide.

Thanks!


In GNU Emacs 27.1 (build 1, x86_64-apple-darwin18.7.0, NS appkit-1671.60 Version 10.14.6 (Build 18G95))
of 2020-08-12 built on builder10-14.porkrind.org
Windowing system distributor 'Apple', version 10.3.2004
System Description:  macOS

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Mark set
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Making completion list...

Configured using:
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Memory information:
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