Test failure with PCRE2 10.47

331s CURRENT_TEST: main.func_regexp_pcre

331s --- /usr/share/mariadb/mariadb-test/main/func_regexp_pcre.result	2025-07-28 19:35:03.000000000 +0000

331s +++ /tmp/tmp.57yAEs5aSK/var/7/log/func_regexp_pcre.reject	2025-10-26 22:46:11.505754917 +0000

331s @@ -791,7 +791,7 @@

331s  1

331s  SET default_regex_flags=DEFAULT;

331s  SELECT 'Aq' RLIKE 'A\\q';

331s -ERROR 42000: Regex error 'unrecognized character follows \ at offset 2'

331s +ERROR 42000: Regex error 'unrecognized character follows \ at offset 3'

331s  SET default_regex_flags='EXTRA';

331s  SELECT 'A' RLIKE 'B';

331s  'A' RLIKE 'B'

331s 

331s Result content mismatch

331s 

331s  - skipping '/tmp/tmp.57yAEs5aSK/var/7/log/main.func_regexp_pcre/'

The test failure is caused by an update to the error text for the affected character location. This changed in 10.47 to match the character reported by Perl's error diagnostic messages (along with other improvements across the board to error messages).

The MariaDB test is a little brittle. PCRE2 does not guarantee to maintain the exact messages in future releases (we reserve the right to change error text, or improve granularity of error codes, for example, by splitting out sub cases).

This has been noticed by a couple of Linux distributions:

OpenSUSE: "MariaDB breaks with pcre2 10.47" https://bugzilla.opensuse.org/show_bug.cgi?id=1252518
Debian: "mariadb: FTBFS with pcre10.47" https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1119866

OpenSUSE appears to have simply disabled this test in their CI build of MariaDB in tumbleweed. Debian has blocked PCRE2 10.47 from Unstable until this is resolved.