bug#39702: 26.3; Permission denied in make-network-process on MacOS 10.15.3

[Phil Roberts]

Evaluating (make-network-process :name "nettest" :buffer "*nettest*"
:host "www.gnu.org" :service "http" :nowait nil :tls-parameters nil) (I
did this by typing it into the *scratch* buffer on a session started via
'emacs -Q', and hitting C-j) triggers an error with the following
backtrace:

Debugger entered--Lisp error: (file-error "make client process failed" 
"Permission denied" :name "nettest" :buffer "*nettest*" :host 
"www.gnu.org" :service "http" :nowait nil :tls-parameters nil)
  make-network-process(:name "nettest" :buffer "*nettest*" :host 
"www.gnu.org" :service "http" :nowait nil :tls-parameters nil)
  eval((make-network-process :name "nettest" :buffer "*nettest*" :host 
"www.gnu.org" :service "http" :nowait nil :tls-parameters nil) nil)
  elisp--eval-last-sexp(t)
  eval-last-sexp(t)
  eval-print-last-sexp(nil)
  funcall-interactively(eval-print-last-sexp nil)
  call-interactively(eval-print-last-sexp nil nil)
  command-execute(eval-print-last-sexp)

This happens using both the build from emacsformacosx.com and that from
homebrew, running on a 2019-model MacBook Pro 13-inch, running MacOS
version 10.15.3 (Catalina).  I've granted emacs every permission I can 
find an
option for in the GUI, to no avail.


In GNU Emacs 26.3 (build 1, x86_64-apple-darwin18.2.0, NS appkit-1671.20 
Version 10.14.3 (Build 18D109))
 of 2019-09-02 built on builder10-14.porkrind.org
Windowing system distributor 'Apple', version 10.3.1894
Recent messages:
[yas] Prepared just-in-time loading of snippets successfully.
Starting Emacs daemon.
When done with this frame, type C-x 5 0

Configured using:
 'configure --with-ns '--enable-locallisppath=/Library/Application
 Support/Emacs/${version}/site-lisp:/Library/Application
 Support/Emacs/site-lisp' --with-modules'

Configured features:
NOTIFY ACL GNUTLS LIBXML2 ZLIB TOOLKIT_SCROLL_BARS NS MODULES THREADS

Important settings:
  value of $LANG: en_GB.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  pyvenv-mode: t
  shell-dirtrack-mode: t
  winner-mode: t
  show-paren-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
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  size-indication-mode: t
  column-number-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 gnus-util rmail rmail-loaddefs
mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils
mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr
mail-utils server py-isort cl-extra yasnippet elec-pair
highlight-indentation flymake-proc flymake warnings thingatpt
company-capf company pcase help-fns radix-tree help-mode elpy elpy-rpc
pyvenv esh-var esh-io esh-cmd esh-opt esh-ext esh-proc esh-arg
esh-groups eshell esh-module esh-mode esh-util elpy-shell elpy-profile
elpy-django s elpy-refactor subr-x python tramp-sh tramp tramp-compat
tramp-loaddefs trampver shell pcomplete parse-time format-spec advice
json map ido grep compile comint ansi-color files-x etags xref project
cus-edit cus-start cus-load wid-edit finder-inf info package easymenu
epg-config url-handlers url-parse auth-source cl-seq eieio eieio-core
cl-macs eieio-loaddefs password-cache url-vars seq byte-opt gv bytecomp
byte-compile cconv edmacro kmacro cl-loaddefs cl-lib winner ring
time-date paren tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel term/ns-win ns-win ucs-normalize mule-util
term/common-win tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page menu-bar rfn-eshadow isearch timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame 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 minibuffer 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 kqueue cocoa ns multi-tty make-network-process emacs)

Memory information:
((conses 16 355666 17376)
 (symbols 48 31674 2)
 (miscs 40 83 234)
 (strings 32 79806 3119)
 (string-bytes 1 2235294)
 (vectors 16 50449)
 (vector-slots 8 917188 13540)
 (floats 8 108 235)
 (intervals 56 241 0)
 (buffers 992 12))