$ /usr/bin/admc_test_upn_edit
********* Start testing of ADMCTestUpnEdit *********
Config: Using QtTest library 5.15.2, Qt 5.15.2 (x86_64-little_endian-lp64 shared (dynamic) release build; by GCC 11.2.1 20210911 (ALT Sisyphus 11.2.1-alt1)), altlinux 9.990
PASS   : ADMCTestUpnEdit::initTestCase()
PASS   : ADMCTestUpnEdit::test_load()
PASS   : ADMCTestUpnEdit::test_emit_edited()
PASS   : ADMCTestUpnEdit::apply_unmodified()
PASS   : ADMCTestUpnEdit::test_apply_suffix()
PASS   : ADMCTestUpnEdit::test_apply_prefix()
PASS   : ADMCTestUpnEdit::test_apply_prefix_and_suffix()
PASS   : ADMCTestUpnEdit::test_reset()
FAIL!  : ADMCTestUpnEdit::test_verify() '!verify_success' returned FALSE. (verify() didn't notice upn conflict)
   Loc: [/usr/src/RPM/BUILD/admc-0.8.2/tests/admc_test_upn_edit.cpp(185)]
QINFO  : ADMCTestUpnEdit::test_verify() AD errors:
QINFO  : ADMCTestUpnEdit::test_verify() "Failed to change attribute userPrincipalName of object conflicting-upn-test-user from \"<unset>\" to \"ADMCTEST-test-user@test.com\". Error: \"Constraint violation\"."
PASS   : ADMCTestUpnEdit::cleanupTestCase()
Totals: 9 passed, 1 failed, 0 skipped, 0 blacklisted, 2499ms
********* Finished testing of ADMCTestUpnEdit *********

При этом ручное редактирование UPN суффиксов и атрибута userPrincipalName выполняется корректно.

Версия admc: 0.8.2-alt1
Версия samba: 4.14.10-alt2

С samba 4.14.8 данный тест проходил успешно.