Specifying the `async_mode` parameter seems to have been a workaround for
packaging on Windows and macOS.  If not given, flask_socketio.SocketIO will
probe for an available asynchronous model, e.g. `eventlet`, and otherwise gets
stuck if `gevent-socketio` is not available.

c.f. https://github.com/onionshare/onionshare/commit/ec7fa4ef16c9e1ba6028ee927c23f76c399a17a6
and  https://github.com/onionshare/onionshare/issues/1510

diff --git a/cli/onionshare_cli/web/web.py b/cli/onionshare_cli/web/web.py
index 64844b5..7e1b095 100644
--- a/cli/onionshare_cli/web/web.py
+++ b/cli/onionshare_cli/web/web.py
@@ -164,10 +164,10 @@ class Web:
         elif self.mode == "chat":
             if self.common.verbose:
                 self.socketio = SocketIO(
-                    async_mode="gevent", logger=True, engineio_logger=True
+                    logger=True, engineio_logger=True
                 )
             else:
-                self.socketio = SocketIO(async_mode="gevent")
+                self.socketio = SocketIO()
             self.socketio.init_app(self.app)
             self.chat_mode = ChatModeWeb(self.common, self)
 
c'>refs</a><a class='active' href='/guix/log/gnu/services/nix.scm'>log</a><a href='/guix/tree/gnu/services/nix.scm?id=8a5bfb267665a821f8bc35c442472c3b8c6e3c3c'>tree</a><a href='/guix/commit/gnu/services/nix.scm?id=8a5bfb267665a821f8bc35c442472c3b8c6e3c3c'>commit</a><a href='/guix/diff/gnu/services/nix.scm?id=8a5bfb267665a821f8bc35c442472c3b8c6e3c3c'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/services/nix.scm'>
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<div class='path'>path: <a href='/guix/log/?id=8a5bfb267665a821f8bc35c442472c3b8c6e3c3c'>root</a>/<a href='/guix/log/gnu?id=8a5bfb267665a821f8bc35c442472c3b8c6e3c3c'>gnu</a>/<a href='/guix/log/gnu/services?id=8a5bfb267665a821f8bc35c442472c3b8c6e3c3c'>services</a>/<a href='/guix/log/gnu/services/nix.scm?id=8a5bfb267665a821f8bc35c442472c3b8c6e3c3c'>nix.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/services/nix.scm?id=8a5bfb267665a821f8bc35c442472c3b8c6e3c3c&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2019-06-12 17:26:28 +0200'>2019-06-12</span></td><td><a href='/guix/commit/gnu/services/nix.scm?id=79d19d7d90c63eca83068cc9b1f22d8020e27563'>services: Import (srfi srfi-26) from the build side.</a><span class='msg-avail'>...<span class='msg-tooltip'>See &lt;https://lists.gnu.org/archive/html/guix-devel/2019-06/msg00119.html&gt;.

* gnu/services/nix.scm (nix-activation): Remove (srfi srfi-26) from (host-)
imported modules.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2019-06-11 21:05:32 +0200'>2019-06-11</span></td><td><a href='/guix/commit/gnu/services/nix.scm?id=2be6b5e2eea9ac084cc22281f64f7a089e46cdae'>services: Add SRFI-26 to Nix activation gexp.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fix the following fatal error on ‘guix system reconfigure’:

Backtrace:
          18 (primitive-load "/home/nckx/.config/guix/current/bin/guix")
In guix/ui.scm:
  1620:12 17 (run-guix-command _ . _)
In ice-9/boot-9.scm:
    829:9 16 (catch _ _ #&lt;procedure 7a7caa2d4c80 at guix/ui.scm:587:2 (key c)&gt; _)
    829:9 15 (catch _ _ #&lt;procedure 7a7caa2d4c98 at guix/ui.scm:710:6 (key proc format-string format-args . …&gt; …)
In guix/scripts/system.scm:
   1325:8 14 (_)
In guix/status.scm:
    768:4 13 (call-with-status-report _ _)
In guix/scripts/system.scm:
   1181:4 12 (process-action _ _ _)
In guix/store.scm:
   623:10 11 (call-with-store _)
  1800:24 10 (run-with-store _ _ #:guile-for-build _ #:system _ #:target _)
In guix/scripts/system.scm:
   920:13  9 (_ _)
    409:8  8 (_ _)
In unknown file:
           7 (primitive-load "/gnu/store/dha7j9gcz3vgb8cy7vfvvaswwsywrrzj-activate")
In ice-9/boot-9.scm:
   260:13  6 (for-each #&lt;procedure primitive-load (_)&gt; _)
In unknown file:
           5 (primitive-load "/gnu/store/ql1xjxrssxm51z2bn2v6l3mlrncij84h-activate-service")
In ice-9/eval.scm:
    619:8  4 (_ #f)
   196:35  3 (_ #f)
   196:27  2 (_ #f)
   223:20  1 (proc #&lt;directory (guile-user) 1fa4140&gt;)
In unknown file:
           0 (%resolve-variable (7 . cut) #&lt;directory (guile-user) 1fa4140&gt;)

ERROR: In procedure %resolve-variable:
error: cut: unbound variable

Reported-by: Alex McGrath on #guix.

* gnu/services/nix.scm (nix-activation): Import and use (srfi srfi-26).
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2019-06-10 09:15:45 +0300'>2019-06-10</span></td><td><a href='/guix/commit/gnu/services/nix.scm?id=47b9614b3110307093382363c0ba70d31f32ef59'>services: Add 'nix-service-type'.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/services/nix.scm: New file.
* gnu/local.mk: Add this.
* doc/guix.texi (Miscellaneous Services): Document this.
</span></span></td><td>Oleg Pykhalov</td></tr>