MySQL 9.x: test_default_value_transaction_isolation_attr-t fails — 'mysql_native_password' plugin is not loaded

[renecannao]

Symptom

TAP test test_default_value_transaction_isolation_attr-t (group mysql90-g3) fails during fixture setup on MySQL 9.x:

File utils.cpp, line 1048, Error: Plugin 'mysql_native_password' is not loaded
TAP test 226/325 'test_default_value_transaction_isolation_attr-t' RC: 1

What the test actually tests (not auth!)

From the file header — covers PR/feature #3466 (default-transaction_isolation per-user attribute):

• Creates several new users with different values for the introduced attribute 'default-transaction_isolation'.
• Connects with each user verifying the value has been correctly tracked for the frontend connection.
• Performs SELECT @@transaction_isolation to verify value is correctly propagated to the backend connection.
• Explicitly sets the value, verifies ProxySQL tracks the change.

Auth plugin is irrelevant to the feature under test.

Why it fails on 9.x

test_default_value_transaction_isolation_attr-t.cpp:225 calls:

int c_users_res = create_extra_users(proxysql_admin, mysql_server, users_configs);

create_extra_users() → create_mysql_user() (in test/tap/tap/utils.cpp:1028) hardcodes IDENTIFIED WITH 'mysql_native_password' in the template. See #5627 for the full helper code.

Proposed fix

Same root and same fix as #5627 — this is not a separate bug, it's the same helper bug surfacing in a different test. Either:

1. Change t_create_user_query in test/tap/tap/utils.cpp:1037–1038 to drop the hardcoded plugin (IDENTIFIED BY only — uses server default).
2. Or add an optional plugin parameter to create_mysql_user() and pass "" by default.

This test doesn't care what plugin the backend uses; the helper-level fix is sufficient. Recommend linking this issue to #5627 and fixing both together.

Evidence from the test log

[proxysql-tester.py:853] msg: File utils.cpp, line 1048, Error: Plugin 'mysql_native_password' is not loaded
[proxysql-tester.py:882] TAP test 226/325 'test_default_value_transaction_isolation_attr-t' RC: 1

Related

Sibling MySQL 9.x issues:

• MySQL 9.x: test_auth_methods-t fails — 'mysql_native_password' plugin is not loaded #5626 test_auth_methods-t
• MySQL 9.x: test_com_reset_connection_com_change_user-t fails — 'mysql_native_password' plugin is not loaded #5627 test_com_reset_connection_com_change_user-t (same helper — fix this together)
• MySQL 9.x: reg_test_4935-caching_sha2-t fails — 'mysql_native_password' plugin is not loaded #5629 reg_test_4935-caching_sha2-t
• MySQL 9.x: test_server_sess_status-t fails — 'mysql_native_password' plugin is not loaded #5630 test_server_sess_status-t (same helper)
• MySQL 9.x: test_sqlite3_pass_exts-t fails — 'mysql_native_password' plugin is not loaded #5631 test_sqlite3_pass_exts-t

Infrastructure: #5625 (dbdeployer-based MySQL 9.0/9.3/9.5 infras).

[coderabbitai]

🔗 Related PRs

#5485 - MySQL/PgSQL Authentication unit tests (Phase 2.2) [merged]
#5538 - CI test fixes: cluster sync, plan counts, test group assignments, and diagnostics [merged]
#5559 - Fix crash when COM_BINLOG_DUMP received with idle backends (#5556) [merged]
#5613 - test(read_only_offline_hard): set default_hostgroup to WHG, not hardcoded 0 [merged]
#5622 - Use MariaDB replication helper for binlog TAP tests [merged]

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