For the record some debug output:
### Stretch before upgrade
# dpkg -S /usr/lib/x86_64-linux-gnu/libma* /usr/lib/x86_64-linux-gnu/libmy*
libmagic1:amd64: /usr/lib/x86_64-linux-gnu/libmagic.so.1
libmagic1:amd64: /usr/lib/x86_64-linux-gnu/libmagic.so.1.0.0
libmailutils5:amd64: /usr/lib/x86_64-linux-gnu/libmailutils.so.5
libmailutils5:amd64: /usr/lib/x86_64-linux-gnu/libmailutils.so.5.0.1
libmariadbclient-dev: /usr/lib/x86_64-linux-gnu/libmariadbclient.a
libmariadbclient-dev: /usr/lib/x86_64-linux-gnu/libmariadbclient.so
libmariadbclient18:amd64: /usr/lib/x86_64-linux-gnu/libmariadbclient.so.18
libmariadbclient18:amd64: /usr/lib/x86_64-linux-gnu/libmariadbclient.so.18.0.0
libmariadbclient-dev: /usr/lib/x86_64-linux-gnu/libmariadbclient_r.a
libmariadbclient-dev: /usr/lib/x86_64-linux-gnu/libmariadbclient_r.so
libmariadbclient-dev: /usr/lib/x86_64-linux-gnu/libmariadbclient_r.so.18
libmariadbclient-dev: /usr/lib/x86_64-linux-gnu/libmariadbclient_r.so.18.0.0
libmariadbclient-dev-compat:amd64: /usr/lib/x86_64-linux-gnu/libmysqlclient.so
libmariadbclient-dev-compat:amd64: /usr/lib/x86_64-linux-gnu/libmysqlclient_r.so
libmariadbd-dev:amd64: /usr/lib/x86_64-linux-gnu/libmysqld.a
libmariadbd-dev:amd64: /usr/lib/x86_64-linux-gnu/libmysqld.so
libmariadbd18:amd64: /usr/lib/x86_64-linux-gnu/libmysqld.so.18
libmariadbclient-dev: /usr/lib/x86_64-linux-gnu/libmysqlservices.a
# find /usr/lib/x86_64-linux-gnu/libma* /usr/lib/x86_64-linux-gnu/libmy* -ls
11878 4 lrwxrwxrwx 1 root root 17 Jun 11
2018 /usr/lib/x86_64-linux-gnu/libmagic.so.1 -> libmagic.so.1.0.0
11869 136 -rw-r--r-- 1 root root 137448 Jun 11
2018 /usr/lib/x86_64-linux-gnu/libmagic.so.1.0.0
43036 4 lrwxrwxrwx 1 root root 21 Dec 25
2016 /usr/lib/x86_64-linux-gnu/libmailutils.so.5 ->
libmailutils.so.5.0.1
43004 820 -rw-r--r-- 1 root root 836960 Dec 25
2016 /usr/lib/x86_64-linux-gnu/libmailutils.so.5.0.1
14428 5440 -rw-r--r-- 1 root root 5570262 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmariadbclient.a
14439 4 lrwxrwxrwx 1 root root 22 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmariadbclient.so ->
libmariadbclient.so.18
14078 4 lrwxrwxrwx 1 root root 26 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmariadbclient.so.18 ->
libmariadbclient.so.18.0.0
14071 4068 -rw-r--r-- 1 root root 4163048 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmariadbclient.so.18.0.0
14440 4 lrwxrwxrwx 1 root root 18 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmariadbclient_r.a ->
libmariadbclient.a
14441 4 lrwxrwxrwx 1 root root 19 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmariadbclient_r.so ->
libmariadbclient.so
14442 4 lrwxrwxrwx 1 root root 19 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmariadbclient_r.so.18 ->
libmariadbclient.so
14443 4 lrwxrwxrwx 1 root root 19 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmariadbclient_r.so.18.0.0 ->
libmariadbclient.so
14454 4 lrwxrwxrwx 1 root root 19 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmysqlclient.so ->
libmariadbclient.so
14455 4 lrwxrwxrwx 1 root root 21 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmysqlclient_r.so ->
libmariadbclient_r.so
14478 28864 -rw-r--r-- 1 root root 29554908 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmysqld.a
14482 4 lrwxrwxrwx 1 root root 15 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmysqld.so -> libmysqld.so.18
14466 16208 -rw-r--r-- 1 root root 16593304 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmysqld.so.18
14429 20 -rw-r--r-- 1 root root 19430 Aug 10
2017 /usr/lib/x86_64-linux-gnu/libmysqlservices.a
# nm -D /usr/lib/x86_64-linux-gnu/libmariadbclient.so.18.0.0 | egrep
'lib(mariadb|mysql)client_'
0000000000000000 A libmariadbclient_16
0000000000000000 A libmariadbclient_18
# ldconfig -p | grep -e mariadb -e mysql
libmysqld.so.18 (libc6,x86-64) => /usr/lib/x86_64-linux-gnu/libmysqld.so.18
libmysqld.so (libc6,x86-64) => /usr/lib/x86_64-linux-gnu/libmysqld.so
libmariadbclient.so.18 (libc6,x86-64) =>
/usr/lib/x86_64-linux-gnu/libmariadbclient.so.18
libmariadbclient.so (libc6,x86-64) =>
/usr/lib/x86_64-linux-gnu/libmariadbclient.so
# curl -IL http://localhost/otrs/index.pl?Action=Admin
HTTP/1.1 200 OK
Date: Mon, 15 Apr 2019 19:02:38 GMT
Server: Apache/2.4.25 (Debian)
X-Powered-By: OTRS 5.0.16 (https://www.otrs.com/)
X-UA-Compatible: IE=edge,chrome=1
X-Frame-Options: SAMEORIGIN
Expires: Tue, 1 Jan 1980 12:00:00 GMT
Cache-Control: no-cache
Pragma: no-cache
X-OTRS-Login: /otrs/index.pl?
Set-Cookie: OTRSBrowserHasCookie=1; path=/otrs/; expires=1y
Vary: Accept-Encoding
Content-Type: text/html; charset=utf-8;
### Stretch after upgrade
Everything else is identical apart from:
# nm -D /usr/lib/x86_64-linux-gnu/libmariadbclient.so.18.0.0 | egrep
'lib(mariadb|mysql)client_'
0000000000000000 A libmariadbclient_16
0000000000000000 A libmariadbclient_18
0000000000000000 A libmysqlclient_16
0000000000000000 A libmysqlclient_18
OTRS works and there is no crashing.
# curl -IL http://localhost/otrs/index.pl?Action=Admin
HTTP/1.1 200 OK
Date: Mon, 15 Apr 2019 19:18:06 GMT
Server: Apache/2.4.25 (Debian)
X-Powered-By: OTRS 5.0.16 (https://www.otrs.com/)
X-UA-Compatible: IE=edge,chrome=1
X-Frame-Options: SAMEORIGIN
Expires: Tue, 1 Jan 1980 12:00:00 GMT
Cache-Control: no-cache
Pragma: no-cache
X-OTRS-Login: /otrs/index.pl?
Set-Cookie: OTRSBrowserHasCookie=1; path=/otrs/; expires=1y
Vary: Accept-Encoding
Content-Type: text/html; charset=utf-8;
