[Python-modules-team] Bug#832130: libapache2-mod-wsgi-py3 is not drop in replaceble for libapache2-mod-wsgi

[Russel Winder]

Package: libapache2-mod-wsgi-py3
Version: 4.3.0-1.1+b1
Severity: important

Dear Maintainer,

I wish to switch a Flas application from Python 2 to Python 3. I successfully installed libapache2-mod-wsgi-py3 which
replaced libapache2-mod-wsgi. In the log I got the message:

[Fri Jul 22 16:33:00.258517 2016] [mpm_prefork:notice] [pid 9081] AH00169: caught SIGTERM, shutting down
[Fri Jul 22 16:33:01.459781 2016] [wsgi:warn] [pid 9612] mod_wsgi: Compiled for Python/3.5.1+.
[Fri Jul 22 16:33:01.459929 2016] [wsgi:warn] [pid 9612] mod_wsgi: Runtime using Python/3.5.2.
[Fri Jul 22 16:33:01.464108 2016] [mpm_prefork:notice] [pid 9612] AH00163: Apache/2.4.23 (Debian) OpenSSL/1.0.2h mod_wsgi/4.3.0 Python/3.5.2 configured -- resuming normal operations
[Fri Jul 22 16:33:01.464272 2016] [core:notice] [pid 9612] AH00094: Command line: '/usr/sbin/apache2'

I then try to restart apache:

root at dimen:~# systemctl restart apache2
Job for apache2.service failed because the control process exited with error code.
See "systemctl status apache2.service" and "journalctl -xe" for details.
root at dimen:~# systemctl status apache2
● apache2.service - LSB: Apache2 web server
   Loaded: loaded (/etc/init.d/apache2; generated; vendor preset: enabled)
  Drop-In: /lib/systemd/system/apache2.service.d
           └─forking.conf
   Active: failed (Result: exit-code) since Fri 2016-07-22 16:56:33 BST; 6s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 10149 ExecStop=/etc/init.d/apache2 stop (code=exited, status=0/SUCCESS)
  Process: 10200 ExecStart=/etc/init.d/apache2 start (code=exited, status=1/FAILURE)

Jul 22 16:56:33 dimen apache2[10200]: The apache2 configtest failed. ... (warning).
Jul 22 16:56:33 dimen apache2[10200]: Output of config test was:
Jul 22 16:56:33 dimen apache2[10200]: AH00526: Syntax error on line 6 of /etc/apache2/sites-enabled/accuconf.winder.org.uk.conf:
Jul 22 16:56:33 dimen apache2[10200]: Invalid command 'WSGIDaemonProcess', perhaps misspelled or defined by a module not included in the server configuration
Jul 22 16:56:33 dimen apache2[10200]: Action 'configtest' failed.
Jul 22 16:56:33 dimen apache2[10200]: The Apache error log may have more information.
Jul 22 16:56:33 dimen systemd[1]: apache2.service: Control process exited, code=exited status=1
Jul 22 16:56:33 dimen systemd[1]: Failed to start LSB: Apache2 web server.
Jul 22 16:56:33 dimen systemd[1]: apache2.service: Unit entered failed state.
Jul 22 16:56:33 dimen systemd[1]: apache2.service: Failed with result 'exit-code'.

It is not clear to me what is going on here since I am not aware that the Apache WSGI commands should be
different between teh two Apache plugins.

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.6.0-1-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages libapache2-mod-wsgi-py3 depends on:
ii  apache2-bin [apache2-api-20120211]  2.4.23-2
ii  libc6                               2.23-2
ii  libpython3.5                        3.5.2-2
ii  python3                             3.5.1-4

libapache2-mod-wsgi-py3 recommends no packages.

libapache2-mod-wsgi-py3 suggests no packages.

-- no debconf information