Bug#854521: apache2: apache not working after a jessie->stretch upgrade

[Vincent Danjean <vdanjean@debian.org>]

Package: apache2
Version: 2.4.25-3
Severity: important

  Hi,

  I just did an jessie->stretch upgrade on one of my machines. The
upgrade run smoothly, no error reported. But, after the upgrade,
apache was not running anymore.
  Looking at the log, I found the following error:

[Tue Feb 07 23:10:05.693502 2017] [mpm_prefork:notice] [pid 17214] AH00171: Graceful restart requested, doing restart
apache2: Syntax error on line 146 of /etc/apache2/apache2.conf: Syntax error on line 2 of /etc/apache2/mods-enabled/access_compat.load: Cannot load /usr/lib/apache2/modules/mod_access_compat.so into server: /usr/lib/apache2/modules/mod_access_compat.so: undefined symbol: ap_get_useragent_host

Google leads me to https://bz.apache.org/bugzilla/show_bug.cgi?id=59842
that give me the fix: just do a plain apache2 restart
# /etc/init.d/apache2 restart

  This full restart should probably be done in the postinst script
if there is a transition between before and after 2.4.19 (as this
is the case for jessie->stretch) according to the previously cited
apache bugzilla report.

  Regards,
    Vincent

-- Package-specific info:

-- System Information:
Debian Release: 9.0
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'stable-updates'), (500, 'stable'), (200, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.7.0-0.bpo.1-amd64 (SMP w/4 CPU cores)
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Init: systemd (via /run/systemd/system)

Versions of packages apache2 depends on:
ii  apache2-bin          2.4.25-3
ii  apache2-data         2.4.25-3
ii  apache2-utils        2.4.25-3
ii  dpkg                 1.18.18
ii  init-system-helpers  1.47
ii  lsb-base             9.20161125
ii  mime-support         3.60
ii  perl                 5.24.1-1
pn  perl:any             <none>
ii  procps               2:3.3.12-3

Versions of packages apache2 recommends:
ii  ssl-cert  1.0.38

Versions of packages apache2 suggests:
pn  apache2-doc                     <none>
ii  apache2-suexec-pristine         2.4.25-3
ii  chromium [www-browser]          56.0.2924.76-1~deb8u1
ii  epiphany-browser [www-browser]  3.22.5-1
ii  firefox-esr [www-browser]       45.7.0esr-1
ii  w3m [www-browser]               0.5.3-34

Versions of packages apache2-bin depends on:
ii  libapr1                  1.5.2-5
ii  libaprutil1              1.5.4-3
ii  libaprutil1-dbd-sqlite3  1.5.4-3
ii  libaprutil1-ldap         1.5.4-3
ii  libc6                    2.24-9
ii  libldap-2.4-2            2.4.44+dfsg-3
ii  liblua5.2-0              5.2.4-1.1+b1
ii  libnghttp2-14            1.18.1-1
ii  libpcre3                 2:8.39-2
ii  libssl1.0.2              1.0.2k-1
ii  libxml2                  2.9.4+dfsg1-2.2
pn  perl:any                 <none>
ii  zlib1g                   1:1.2.8.dfsg-5

Versions of packages apache2-bin suggests:
pn  apache2-doc                     <none>
ii  apache2-suexec-pristine         2.4.25-3
ii  chromium [www-browser]          56.0.2924.76-1~deb8u1
ii  epiphany-browser [www-browser]  3.22.5-1
ii  firefox-esr [www-browser]       45.7.0esr-1
ii  w3m [www-browser]               0.5.3-34

Versions of packages apache2 is related to:
ii  apache2      2.4.25-3
ii  apache2-bin  2.4.25-3

-- Configuration Files:
/etc/apache2/apache2.conf changed [not included]
/etc/apache2/mods-available/userdir.conf changed [not included]
/etc/apache2/sites-available/000-default.conf changed [not included]
/etc/logrotate.d/apache2 changed [not included]

-- no debconf information