Hello!

I am testing MySQL version 5.7.40 with percona57-pam-for-mysql-5.7.40.43 and get an error when I try to load the module from inside mysql. 

root@localhost [(none)]> INSTALL PLUGIN auth_pam SONAME 'auth_pam.so';
ERROR 2013 (HY000): Lost connection to MySQL server during query

When I tail the log file when running the command above I get this this below:

--------

Version: '5.7.40-log'  socket: '/tmp/mysql.sock'  port: 3306  Source distribution
19:10:54 UTC - mysqld got signal 11 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
Attempting to collect some information that could help diagnose the problem.
As this is a crash and something is definitely wrong, the information
collection process might fail.

key_buffer_size=268435456
read_buffer_size=131072
max_used_connections=1
max_threads=151
thread_count=1
connection_count=1
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 322099 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x87b607000
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
stack_bottom = 7fffdb395f58 thread_stack 0x40000
0x13f3b68 <my_print_stacktrace+0x38> at /usr/local/libexec/mysqld
0x13518ae <handle_fatal_signal+0x2be> at /usr/local/libexec/mysqld
0x80188a580 <pthread_sigmask+0x540> at /lib/libthr.so.3
0x801889b3f <pthread_setschedparam+0x82f> at /lib/libthr.so.3
0x7ffffffff8a3 <???> at ???
0x16ca190 <pfs_memory_claim_v1+0xf0> at /usr/local/libexec/mysqld
0x8023e8c99 <auth_pam_talk_perform+0x169> at /usr/local/lib/mysql/plugin/auth_pam.so
0xc99fec <_Z40plugin_register_builtin_and_init_core_sePiPPc+0xb7c> at /usr/local/libexec/mysqld
0xc9d6d5 <_ZN22Sql_cmd_install_plugin7executeEP3THD+0x3a5> at /usr/local/libexec/mysqld
0xcaface <_Z21mysql_execute_commandP3THDb+0x91e> at /usr/local/libexec/mysqld
0xcae5c9 <_Z11mysql_parseP3THDP12Parser_state+0x429> at /usr/local/libexec/mysqld
0xcad1a9 <_Z16dispatch_commandP3THDPK8COM_DATA19enum_server_command+0x1039> at /usr/local/libexec/mysqld
0xcadb5e <_Z10do_commandP3THD+0x17e> at /usr/local/libexec/mysqld
0xf00df4 <handle_connection+0x1e4> at /usr/local/libexec/mysqld
0x16c4a23 <pfs_spawn_thread+0x133> at /usr/local/libexec/mysqld

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (87b643aa0): INSTALL PLUGIN auth_pam SONAME 'auth_pam.so'
Connection ID (thread ID): 2
Status: NOT_KILLED

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If I load the module with my.cnf MySQL fails to start.

I tried to use the pam version percona-pam-for-mysql-5.7.39.42 and get the same errors. This is the version that is in the ports tree.

Testing with this version percona57-pam-for-mysql-5.7.36.39 works just fine and the module loads inside of mysql or loading it from my.cnf.