bug#61637: 30.0.50; Fix Eglot tests that need HOME=~USER

[Eli Zaretskii]

> From: Basil Contovounesios <contovob@tcd.ie>
> Cc: Eli Zaretskii <eliz@gnu.org>,  61637@debbugs.gnu.org
> Date: Sat, 04 Mar 2023 17:19:26 +0000
> 
> João Távora [2023-03-04 01:04 +0000] wrote:
> 
> > Another option is to have eglot-tests.el read a new environment var:
> >
> > diff --git a/test/lisp/progmodes/eglot-tests.el 
> > b/test/lisp/progmodes/eglot-tests.el
> > index 5d5de59a19a..ad994915c52 100644
> > --- a/test/lisp/progmodes/eglot-tests.el
> > +++ b/test/lisp/progmodes/eglot-tests.el
> > @@ -116,9 +116,7 @@ eglot--call-with-fixture
> >                     ;; installations for LSP servers like pylsp, making
> >                     ;; these tests mostly useless, so we hack around it
> >                     ;; here with a great big hack.
> > -                   ,(format "HOME=%s"
> > -                            (if (file-exists-p home) home
> > -                              (format "/home/%s" (getenv "USER")))))
> > +                   ,(format "HOME=%s" (or (getenv "EGLOT_REAL_HOME") 
> > (getenv "HOME"))))
> >                   process-environment))
> >                 ;; Prevent "Can't guess python-indent-offset ..." messages.
> >                 (python-indent-guess-indent-offset-verbose . nil)
> >
> > This is acceptable for Eglot devs like me, but other devs that don't
> > know about this variable will still be confused. WDYT?
> 
> So the suggestion is for parties interested in running the full
> unadulterated Eglot suite to set this environment variable, thus opting
> into using their HOME or any other HOME-like environment they may have
> set up?

For process-environment only, i.e. for the LSP server that is being
started.  Presumably, not for Emacs itself.