InnoDB: Failing assertion: dict_tf2_is_valid(flags, flags2) during ADD COLUMN

2021-09-09 12:22:54 0x7fc56cbea700 InnoDB: Assertion failure in file /home/buildbot/buildbot/build/mariadb-10.4.20/storage/innobase/dict/dict0mem.cc line 152
InnoDB: Failing assertion: dict_tf2_is_valid(flags, flags2)
InnoDB: We intentionally generate a memory trap.
InnoDB: Submit a detailed bug report to https://jira.mariadb.org/
InnoDB: If you get repeated assertion failures or crashes, even
InnoDB: immediately after the mysqld startup, there may be
InnoDB: corruption in the InnoDB tablespace. Please refer to
InnoDB: https://mariadb.com/kb/en/library/innodb-recovery-modes/
InnoDB: about forcing recovery.
210909 12:22:54 [ERROR] mysqld got signal 6 ;
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.

To report this bug, see https://mariadb.com/kb/en/reporting-bugs

We will try our best to scrape up some info that will hopefully help
diagnose the problem, but since we have already crashed,
something is definitely wrong and this may fail.

Server version: 10.4.20-MariaDB-1:10.4.20+maria~focal
key_buffer_size=16777216
read_buffer_size=131072
max_used_connections=13
max_threads=153
thread_count=10
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 353082 K bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x7fc4d801e438
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 = 0x7fc56cbe9dd8 thread_stack 0x30000
/usr/sbin/mysqld(my_print_stacktrace+0x32)[0x555d47e5ae82]
/usr/sbin/mysqld(handle_fatal_signal+0x55d)[0x555d4790e82d]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x153c0)[0x7fc57122b3c0]
/lib/x86_64-linux-gnu/libc.so.6(gsignal+0xcb)[0x7fc570d3118b]
/lib/x86_64-linux-gnu/libc.so.6(abort+0x12b)[0x7fc570d10859]
/usr/sbin/mysqld(+0x5b7b85)[0x555d475d8b85]
/usr/sbin/mysqld(+0x5c9f01)[0x555d475eaf01]
/usr/sbin/mysqld(+0xad2c16)[0x555d47af3c16]
/usr/sbin/mysqld(+0xada493)[0x555d47afb493]
/usr/sbin/mysqld(+0x763814)[0x555d47784814]
/usr/sbin/mysqld(_Z17mysql_alter_tableP3THDPK25st_mysql_const_lex_stringS3_P14HA_CREATE_INFOP10TABLE_LISTP10Alter_infojP8st_orderb+0x3611)[0x555d47790bc1]
/usr/sbin/mysqld(_ZN19Sql_cmd_alter_table7executeEP3THD+0x34f)[0x555d477e9e7f]
/usr/sbin/mysqld(_Z21mysql_execute_commandP3THD+0x1168)[0x555d476e62b8]
/usr/sbin/mysqld(_Z11mysql_parseP3THDPcjP12Parser_statebb+0x223)[0x555d476ed273]
/usr/sbin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcjbb+0x134d)[0x555d476ef78d]
/usr/sbin/mysqld(_Z10do_commandP3THD+0x140)[0x555d476f19c0]
/usr/sbin/mysqld(_Z24do_handle_one_connectionP7CONNECT+0x22e)[0x555d477e591e]
/usr/sbin/mysqld(handle_one_connection+0x3f)[0x555d477e5a3f]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x9609)[0x7fc57121f609]
/lib/x86_64-linux-gnu/libc.so.6(clone+0x43)[0x7fc570e0d293]

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (0x7fc4d80563b0): ALTER TABLE oc_talk_rooms ADD sip_enabled SMALLINT UNSIGNED DEFAULT 0 NOT NULL, ADD description LONGTEXT DEFAULT NULL, ADD listable SMALLINT UNSIGNED DEFAULT 0, ADD call_flag INT DEFAULT 0 NOT NULL

Connection ID (thread ID): 171879
Status: NOT_KILLED

Optimizer switch: index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on

The manual page at https://mariadb.com/kb/en/how-to-produce-a-full-stack-trace-for-mysqld/ contains
information that should help you find out what is causing the crash.
Writing a core file...
Working directory at /var/lib/mysql
Resource Limits:
Limit Soft Limit Hard Limit Units
Max cpu time unlimited unlimited seconds
Max file size unlimited unlimited bytes
Max data size unlimited unlimited bytes
Max stack size 8388608 unlimited bytes
Max core file size 0 unlimited bytes
Max resident set unlimited unlimited bytes
Max processes 31493 31493 processes
Max open files 32768 32768 files
Max locked memory 65536 65536 bytes
Max address space unlimited unlimited bytes
Max file locks unlimited unlimited locks
Max pending signals 31493 31493 signals
Max msgqueue size 819200 819200 bytes
Max nice priority 0 0
Max realtime priority 0 0
Max realtime timeout unlimited unlimited us
Core pattern: |/usr/share/apport/apport %p %s %c %d %P %E

2021-09-09 12:23:02 0 [Note] InnoDB: Using Linux native AIO
2021-09-09 12:23:02 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2021-09-09 12:23:02 0 [Note] InnoDB: Uses event mutexes
2021-09-09 12:23:02 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2021-09-09 12:23:02 0 [Note] InnoDB: Number of pools: 1
2021-09-09 12:23:02 0 [Note] InnoDB: Using generic crc32 instructions
2021-09-09 12:23:02 0 [Note] mysqld: O_TMPFILE is not supported on /tmp (disabling future attempts)
2021-09-09 12:23:02 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2021-09-09 12:23:02 0 [Note] InnoDB: Completed initialization of buffer pool
2021-09-09 12:23:02 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2021-09-09 12:23:02 0 [Note] InnoDB: Starting crash recovery from checkpoint LSN=130872279427
2021-09-09 12:23:02 0 [Note] InnoDB: 128 out of 128 rollback segments are active.
2021-09-09 12:23:02 0 [Note] InnoDB: Removed temporary tablespace data file: "ibtmp1"
2021-09-09 12:23:02 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2021-09-09 12:23:02 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2021-09-09 12:23:02 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
2021-09-09 12:23:02 0 [Note] InnoDB: Waiting for purge to start
2021-09-09 12:23:02 0 [Note] InnoDB: 10.4.20 started; log sequence number 130872279436; transaction id 48766583
2021-09-09 12:23:02 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
2021-09-09 12:23:02 0 [Note] Plugin 'FEEDBACK' is disabled.
2021-09-09 12:23:02 0 [Note] Server socket created on IP: '127.0.0.1'.
2021-09-09 12:23:02 0 [Note] Reading of all Master_info entries succeeded
2021-09-09 12:23:02 0 [Note] Added new Master_info '' to hash table
2021-09-09 12:23:02 0 [Note] /usr/sbin/mysqld: ready for connections.
Version: '10.4.20-MariaDB-1:10.4.20+maria~focal' socket: '/var/run/mysqld/mysqld.sock' port: 3306 mariadb.org binary distribution
2021-09-09 12:23:03 0 [Note] InnoDB: Buffer pool(s) load completed at 210909 12:23:03