Public bug reported: I am reporting this bug in response to a discussion in [gnome- terminal][1]. It looks like there has possibly been a regression from EOAN to FOCAL in pcre2.
Given the following regex: <code>(?<APOS_START>(?<='))?" "(?(DEFINE)(?<S4>(?x: (?: [0-9] | [1-9][0-9] | 1[0-9]{2} | 2[0-4][0-9] | 25[0-5] ) (?! [0-9] ) )))" "(?(DEFINE)(?<IPV4>(?x: (?: (?&S4) \\. ){3} (?&S4) )))" "(?(DEFINE)(?<S6>[[:xdigit:]]{1,4})(?<CS6>:(?&S6))(?<S6C>(?&S6):))" "(?(DEFINE)(?<IPV6>(?x: (?: " "(?x: :: )" " | " "(?x: : (?&CS6){1,7} )" " | " "(?x: (?! (?: [[:xdigit:]]*: ){8} ) (?&S6C){1,6} (?&CS6){1,6} )" " | " "(?x: (?&S6C){1,7} : )" " | " "(?x: (?&S6C){7} (?&S6) )" " | (?: " "(?x: (?&S6C){6} )" " | " "(?x: :: (?&S6C){0,5} )" " | " "(?x: (?! (?: [[:xdigit:]]*: ){7} ) (?&S6C){1,4} (?&CS6){1,4} ) :" " | " "(?x: (?&S6C){1,5} : )" " ) (?&IPV4) ) (?! [.:[:xdigit:]] ) )))" "(?(DEFINE)(?<PATH_INNER>(?x: (?: " "[-[:alnum:]\\Q_$.+!*,:;@&=?/~#|%'\\E]" "* (?: \\( (?&PATH_INNER) \\) | \\[ (?&PATH_INNER) \\] ) )* " "[-[:alnum:]\\Q_$.+!*,:;@&=?/~#|%'\\E]" "* )))" "(?(DEFINE)(?<PATH>(?x: (?: " "[-[:alnum:]\\Q_$.+!*,:;@&=?/~#|%'\\E]" "* (?: \\( (?&PATH_INNER) \\) | \\[ (?&PATH_INNER) \\] ) )* (?: " "[-[:alnum:]\\Q_$.+!*,:;@&=?/~#|%'\\E]" "* (?(<APOS_START>)" "[-[:alnum:]\\Q_$+*:@&=/~#|%\\E]" "|" "[-[:alnum:]\\Q_$+*:@&=/~#|%'\\E]" ") )? )))" "(?<!(?:" "(?x: [-[:alnum:]] | (?! [[:ascii:]] ) [[:graph:]] )" "|[.]))(?=(?i:www|ftp))" "(?x: (?: " "(?x: [-[:alnum:]] | (?! [[:ascii:]] ) [[:graph:]] )" "+ \\. )* " "(?x: [-[:alnum:]] | (?! [[:ascii:]] ) [[:graph:]] )" "* (?! [0-9] ) " "(?x: [-[:alnum:]] | (?! [[:ascii:]] ) [[:graph:]] )" "+ )" "(?x: \\:" "(?x: (?: [1-9][0-9]{0,3} | [1-5][0-9]{4} | 6[0-4][0-9]{3} | 65[0-4][0-9]{2} | 655[0-2][0-9] | 6553[0-5] ) (?! [0-9] ) )" " )?" "(?x: /(?&PATH) )?</code> And the following input: www.foo.bar/baz WWW3.foo.bar/baz FTP.FOO.BAR/BAZ ftpxy.foo.bar/baz The regex should match but does actually not match. In EOAN this still worked as I have just confirmed in a virtual machine. [1]: https://gitlab.gnome.org/GNOME/gnome-terminal/issues/221 ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: libpcre2-8-0 10.34-7 ProcVersionSignature: Ubuntu 5.4.0-14.17-generic 5.4.18 Uname: Linux 5.4.0-14-generic x86_64 ApportVersion: 2.20.11-0ubuntu17 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Sun Feb 23 15:49:32 2020 InstallationDate: Installed on 2020-02-04 (18 days ago) InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017) SourcePackage: pcre2 UpgradeStatus: Upgraded to focal on 2020-02-22 (0 days ago) ** Affects: pcre2 (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug focal -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1864364 Title: Possible Regession: PCRE2 fails to match regex To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pcre2/+bug/1864364/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs