uwsgi-plugin-python3 failed to install

[Vitalii]

I expected the package uwsgi-plugin-python3 will be installed with apt-get install. But instead it failed with error "/var/lib/dpkg/info/uwsgi-plugin-python3.postinst: 61: [: Illegal number:".

# apt-get install uwsgi-plugin-python3
Reading package lists... Done
Building dependency tree
Reading state information... Done
Suggested packages:
  python3-uwsgidecorators
The following NEW packages will be installed
  uwsgi-plugin-python3
0 to upgrade, 1 to newly install, 0 to remove and 0 not to upgrade.
Need to get 0 B/73.7 kB of archives.
After this operation, 259 kB of additional disk space will be used.
Selecting previously unselected package uwsgi-plugin-python3.
(Reading database ... 101126 files and directories currently installed.)
Preparing to unpack .../uwsgi-plugin-python3_2.0.12-5ubuntu3_amd64.deb ...
Unpacking uwsgi-plugin-python3 (2.0.12-5ubuntu3) ...
Processing triggers for man-db (2.7.5-1) ...
Setting up uwsgi-plugin-python3 (2.0.12-5ubuntu3) ...
/var/lib/dpkg/info/uwsgi-plugin-python3.postinst: 61: [: Illegal number:

# lsb_release -rd
Description: Ubuntu 16.04.1 LTS
Release: 16.04

# apt-cache policy uwsgi-plugin-python3
uwsgi-plugin-python3:
  Installed: 2.0.12-5ubuntu3
  Candidate: 2.0.12-5ubuntu3
  Version table:
 *** 2.0.12-5ubuntu3 500
        500 http://gb.archive.ubuntu.com/ubuntu xenial/universe amd64 Packages
        100 /var/lib/dpkg/status

[peter toneby (peter-toneby)]

I see this as well. Seems to make the python35 plugin not loadable since I have it in the plugins line in myservice.ini-file, but python2 is used according to the log. The import site issue is related to the fact it tries to use python2.7 in a venv from python3.5. I added it in an earlier (failed) attempt to use uwsgi (but that attempt did have the python34 module working, that was on the last LTS release (whichever version that was))

# apt install --reinstall uwsgi-plugin-python3
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 16 not upgraded.
Need to get 0 B/73.7 kB of archives.
After this operation, 0 B of additional disk space will be used.
(Reading database ... 46609 files and directories currently installed.)
Preparing to unpack .../uwsgi-plugin-python3_2.0.12-5ubuntu3_amd64.deb ...
Unpacking uwsgi-plugin-python3 (2.0.12-5ubuntu3) over (2.0.12-5ubuntu3) ...
Processing triggers for man-db (2.7.5-1) ...
Setting up uwsgi-plugin-python3 (2.0.12-5ubuntu3) ...
/var/lib/dpkg/info/uwsgi-plugin-python3.postinst: 61: [: Illegal number:

# cat /var/log/uwsgi/app/service.log
Mon Sep 5 22:22:06 2016 - *** Starting uWSGI 2.0.12-debian (64bit) on [Mon Sep 5 22:22:05 2016] ***
Mon Sep 5 22:22:06 2016 - compiled with version: 5.3.1 20160412 on 13 April 2016 08:36:06
Mon Sep 5 22:22:06 2016 - os: Linux-3.13.0-93-generic #140-Ubuntu SMP Mon Jul 18 21:21:05 UTC 2016
Mon Sep 5 22:22:06 2016 - nodename: thehost
Mon Sep 5 22:22:06 2016 - machine: x86_64
Mon Sep 5 22:22:06 2016 - clock source: unix
Mon Sep 5 22:22:06 2016 - pcre jit disabled
Mon Sep 5 22:22:06 2016 - detected number of CPU cores: 1
Mon Sep 5 22:22:06 2016 - current working directory: /
Mon Sep 5 22:22:06 2016 - writing pidfile to /run/uwsgi/app/myservice/pid
Mon Sep 5 22:22:06 2016 - detected binary path: /usr/bin/uwsgi-core
Mon Sep 5 22:22:06 2016 - setgid() to 33
Mon Sep 5 22:22:06 2016 - setuid() to 33
Mon Sep 5 22:22:06 2016 - chdir() to /home/user/myservice/dist
Mon Sep 5 22:22:06 2016 - your processes number limit is 7474
Mon Sep 5 22:22:06 2016 - your memory page size is 4096 bytes
Mon Sep 5 22:22:06 2016 - detected max file descriptor number: 1024
Mon Sep 5 22:22:06 2016 - building mime-types dictionary from file /etc/mime.types...Mon Sep 5 22:22:06 2016 - 552 entry found
Mon Sep 5 22:22:06 2016 - lock engine: pthread robust mutexes
Mon Sep 5 22:22:06 2016 - thunder lock: disabled (you can enable it with --thunder-lock)
Mon Sep 5 22:22:06 2016 - uwsgi socket 0 bound to UNIX address /run/uwsgi/app/myservice/socket fd 3
Mon Sep 5 22:22:06 2016 - Python version: 2.7.12 (default, Jul 1 2016, 15:12:24) [GCC 5.4.0 20160609]
Mon Sep 5 22:22:06 2016 - Set PythonHome to /home/user/myservice/
Mon Sep 5 22:22:06 2016 - Python main interpreter initialized at 0x1e92140
Mon Sep 5 22:22:06 2016 - python threads support enabled
Mon Sep 5 22:22:06 2016 - your server socket listen backlog is limited to 100 connections
Mon Sep 5 22:22:06 2016 - your mercy for graceful operations on workers is 60 seconds
Mon Sep 5 22:22:06 2016 - mapped 145536 bytes (142 KB) for...

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[peter toneby (peter-toneby)]

Looking at the postinst script it seems likely you want to compare to $? rather than $BINARY_IS_UWSGI_ALTERNATIVE. Although I'm not quite sure why you pipe through true in the last step since that will make sure 0 is always the return code. Grep returns 0 if a line was found, 1 if not and 2 if an error occured so to me it looks like you should be covered by that.

I did change the if statement on line 61 to
   if [ $? -eq 0 ]; then
And that seems to work, at least the package installed without any errors and I got the /usr/bin/uwsgi_python3 link that ultimatly points at uwsgi-core.

While checking the alternatives I realized that I had the python2-plugin installed so I uninstalled it and got python3 working.

Now I just have sort out some other uwsgi-configuration issue and I'll be all good.

[Kye Russell (kye.russell-thecut)]

Is this still an issue being looked into? It's suddenly started presenting itself to me.

[Andreas Hasenack (ahasenack)]

Kye, could you elaborate on what you are seeing? I just tried a simple "apt install uwsgi-plugin-python3" on a fresh xenial container, and it worked:
root@xenial:~# apt install uwsgi-plugin-python3
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  libjansson4 libmatheval1 libsodium18 libzmq5 uwsgi-core
Suggested packages:
  nginx-full | cherokee | libapache2-mod-proxy-uwsgi | libapache2-mod-uwsgi | libapache2-mod-ruwsgi uwsgi-plugins-all uwsgi-extra python3-uwsgidecorators
The following NEW packages will be installed:
  libjansson4 libmatheval1 libsodium18 libzmq5 uwsgi-core uwsgi-plugin-python3
0 upgraded, 6 newly installed, 0 to remove and 2 not upgraded.
Need to get 73.8 kB/926 kB of archives.
After this operation, 3,295 kB of additional disk space will be used.
Do you want to continue? [Y/n]
(...)
Setting up uwsgi-core (2.0.12-5ubuntu3.2) ...
Setting up uwsgi-plugin-python3 (2.0.12-5ubuntu3.2) ...
/var/lib/dpkg/info/uwsgi-plugin-python3.postinst: 61: [: Illegal number:
Processing triggers for libc-bin (2.23-0ubuntu11) ...
root@xenial:~# echo $?
0
root@xenial:~#

The comparison in line 61 is correct to be a number, because it's counting the occurrences of /uwsgi_python3. That should always output a number, 0 or higher.

Maybe that code changed, but now it reads:
      BINARY_IS_UWSGI_ALTERNATIVE="$(\
        update-alternatives --list uwsgi 2>/dev/null \
        | grep -c '/uwsgi_python3$' | true \
      )"
      if [ "$BINARY_IS_UWSGI_ALTERNATIVE" -eq 0 ]; then <--- line 61

[Andreas Hasenack (ahasenack)]

Apologies, after reproducing #1562237 which was about the python2 module, I see what's going on here. It's the "| true" bit, which should have been "|| true". In fact, that is fixed in later versions of the package:
      BINARY_IS_UWSGI_ALTERNATIVE="$(\
        update-alternatives --list uwsgi 2>/dev/null \
        | grep -c '/uwsgi_@@plugin_alternatives_stem@@$' || true \
      )"
      if [ "$BINARY_IS_UWSGI_ALTERNATIVE" -eq 0 ]; then

This was fixed in debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=818116

[Andreas Hasenack (ahasenack)]

Pressed enter too soon. I meant to add it's fixed in debian since 2.0.12-6

[Athos Ribeiro (athos-ribeiro)]

Since this has been fixed since Bionic, and Xenial is no longer under standard support, I am closing this as wontfix.