bug#57981: 13.1.1; Evince synctex: env variables not inherited

[Fabian Thomas]

When using TeX-view to open the current configured pdf with synctex
forward search, the evince pdf viewer does not inherit or load
environment variables from e.g., ~/.zshenv.

Other viewers like zathura or okular work perfectly fine.

When I do cat /proc/`pidof okular`/environ, I get the full environment
with variables from my ~/.zshenv, but when I do
cat /proc/`pidof evince`/environ I get a plain version with no custom
variables. When I start evince from command line everything works fine.

I suspect, that this is some issue about how evince is started via dbus
for synctex support.

Here is the output of cat /proc/`pidof evince`/environ when started from
emacs:
SHELL=/bin/zshDBUS_STARTER_ADDRESS=unix:path=/run/user/1000/bus,guid=bfDISPLAY=:0XDG_RUNTIME_DIR=/run/user/1000LC_MONETARY=de_DE.UTF-8LC_NUMERIC=de_DE.UTF-8PATH=/usr/local/bin:/usr/binMAIL=/var/spool/mail/fabianSYSTEMD_EXEC_PID=2137DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus,guid=bfXAUTHORITY=/home/fabian/.XauthorityUSER=fabianDBUS_STARTER_BUS_TYPE=sessionMANAGERPID=2051LANG=en_US.UTF-8LC_COLLATE=CHOME=/home/fabianLOGNAME=fabian

I use the following elisp code to set the viewer to evince (doom emacs):
(after! tex
        (setq TeX-view-program-selection '((output-pdf "Evince") (output-pdf 
"Zathura") (output-pdf "Okular") (output-html "xdg-open"))))




Emacs  : GNU Emacs 28.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.33, 
cairo version 1.17.6)
 of 2022-04-28
Package: 13.1.1

current state:
==============
(setq
 AUCTeX-date "2022-02-22"
 window-system 'x
 LaTeX-version "2e"
 TeX-style-path '("~/.emacs.d/auctex" 
"/home/fabian/.emacs.d/.local/straight/build-28.1/auctex/style"
                  "/home/fabian/.emacs.d/.local/cache/auctex/.auctex-auto" 
"/home/fabian/.emacs.d/.local/cache/auctex/.auctex-style"
                  ".auctex-auto" ".auctex-style")
 TeX-auto-save t
 TeX-parse-self t
 TeX-master t
 TeX-command-list '(("TeX" "%(PDF)%(tex) %(file-line-error) %`%(extraopts) 
%S%(PDFout)%(mode)%' %(output-dir) %t" TeX-run-TeX nil
                     (plain-tex-mode ams-tex-mode texinfo-mode) :help "Run 
plain TeX")
                    ("LaTeX" "%`%l%(mode)%' %T" TeX-run-TeX nil (latex-mode 
doctex-mode) :help "Run LaTeX")
                    ("Makeinfo" "makeinfo %(extraopts) %(o-dir) %t" 
TeX-run-compile nil (texinfo-mode) :help
                     "Run Makeinfo with Info output")
                    ("Makeinfo HTML" "makeinfo %(extraopts) %(o-dir) --html %t" 
TeX-run-compile nil (texinfo-mode) :help
                     "Run Makeinfo with HTML output")
                    ("AmSTeX" "amstex %(PDFout) %`%(extraopts) %S%(mode)%' 
%(output-dir) %t" TeX-run-TeX nil (ams-tex-mode) :help
                     "Run AMSTeX")
                    ("ConTeXt" "%(cntxcom) --once --texutil %(extraopts) 
%(execopts)%t" TeX-run-TeX nil (context-mode) :help
                     "Run ConTeXt once")
                    ("ConTeXt Full" "%(cntxcom) %(extraopts) %(execopts)%t" 
TeX-run-TeX nil (context-mode) :help
                     "Run ConTeXt until completion")
                    ("BibTeX" "bibtex %(O?aux)" TeX-run-BibTeX nil
                     (plain-tex-mode latex-mode doctex-mode ams-tex-mode 
texinfo-mode context-mode) :help "Run BibTeX")
                    ("Biber" "biber %(output-dir) %s" TeX-run-Biber nil 
(plain-tex-mode latex-mode doctex-mode ams-tex-mode texinfo-mode)
                     :help "Run Biber")
                    ("Texindex" "texindex %s.??" TeX-run-command nil 
(texinfo-mode) :help "Run Texindex")
                    ("Texi2dvi" "%(PDF)texi2dvi %t" TeX-run-command nil 
(texinfo-mode) :help "Run Texi2dvi or Texi2pdf")
                    ("View" "%V" TeX-run-discard-or-function t t :help "Run 
Viewer")
                    ("Print" "%p" TeX-run-command t t :help "Print the file")
                    ("Queue" "%q" TeX-run-background nil t :help "View the 
printer queue" :visible TeX-queue-command)
                    ("File" "%(o?)dvips %d -o %f " TeX-run-dvips t 
(plain-tex-mode latex-mode doctex-mode ams-tex-mode texinfo-mode)
                     :help "Generate PostScript file")
                    ("Dvips" "%(o?)dvips %d -o %f " TeX-run-dvips nil 
(plain-tex-mode latex-mode doctex-mode ams-tex-mode texinfo-mode)
                     :help "Convert DVI file to PostScript")
                    ("Dvipdfmx" "dvipdfmx -o %(O?pdf) %d" TeX-run-dvipdfmx nil
                     (plain-tex-mode latex-mode doctex-mode ams-tex-mode 
texinfo-mode) :help "Convert DVI file to PDF with dvipdfmx")
                    ("Ps2pdf" "ps2pdf %f %(O?pdf)" TeX-run-ps2pdf nil 
(plain-tex-mode latex-mode doctex-mode ams-tex-mode texinfo-mode)
                     :help "Convert PostScript file to PDF")
                    ("Glossaries" "makeglossaries %(d-dir) %s" TeX-run-command 
nil
                     (plain-tex-mode latex-mode doctex-mode ams-tex-mode 
texinfo-mode) :help "Run makeglossaries to create glossary file")
                    ("Index" "makeindex %(O?idx)" TeX-run-index nil 
(plain-tex-mode latex-mode doctex-mode ams-tex-mode texinfo-mode)
                     :help "Run makeindex to create index file")
                    ("upMendex" "upmendex %(O?idx)" TeX-run-index t 
(plain-tex-mode latex-mode doctex-mode ams-tex-mode texinfo-mode)
                     :help "Run upmendex to create index file")
                    ("Xindy" "texindy %s" TeX-run-command nil (plain-tex-mode 
latex-mode doctex-mode ams-tex-mode texinfo-mode) :help
                     "Run xindy to create index file")
                    ("Check" "chktex -v6 -H %s" TeX-run-compile nil 
(latex-mode) :help "Check LaTeX file for correctness")
                    ("ChkTeX" "chktex -v6 %s" TeX-run-compile nil (latex-mode) 
:help "Check LaTeX file for common mistakes")
                    ("Spell" "(TeX-ispell-document \"\")" TeX-run-function nil 
t :help "Spell-check the document")
                    ("Clean" "TeX-clean" TeX-run-function nil t :help "Delete 
generated intermediate files")
                    ("Clean All" "(TeX-clean t)" TeX-run-function nil t :help 
"Delete generated intermediate and output files")
                    ("Other" "" TeX-run-command t t :help "Run an arbitrary 
command"))
 )