+ '/\x{1/' => 'Missing right brace on \x{} {#} m/\x{1{#}/',
+ '/\x{X/' => 'Missing right brace on \x{} {#} m/\x{{#}X/',
+
+ '/[\x{X]/' => 'Missing right brace on \x{} {#} m/[\x{{#}X]/',
+ '/[\x{A]/' => 'Missing right brace on \x{} {#} m/[\x{A{#}]/',
+
+ '/\o{1/' => 'Missing right brace on \o{ {#} m/\o{1{#}/',
+ '/\o{X/' => 'Missing right brace on \o{ {#} m/\o{{#}X/',
+
+ '/[\o{X]/' => 'Missing right brace on \o{ {#} m/[\o{{#}X]/',
+ '/[\o{7]/' => 'Missing right brace on \o{ {#} m/[\o{7{#}]/',
+
+ '/[[:barf:]]/' => 'POSIX class [:barf:] unknown {#} m/[[:barf:]{#}]/',
+
+ '/[[=barf=]]/' => 'POSIX syntax [= =] is reserved for future extensions {#} m/[[=barf=]{#}]/',
+
+ '/[[.barf.]]/' => 'POSIX syntax [. .] is reserved for future extensions {#} m/[[.barf.]{#}]/',
+
+ '/[z-a]/' => 'Invalid [] range "z-a" {#} m/[z-a{#}]/',
+
+ '/\p/' => 'Empty \p{} {#} m/\p{#}/',
+
+ '/\P{}/' => 'Empty \P{} {#} m/\P{{#}}/',
+ '/(?[[[:word]]])/' => "Unmatched ':' in POSIX class {#} m/(?[[[:word{#}]]])/",
+ '/(?[[:word]])/' => "Unmatched ':' in POSIX class {#} m/(?[[:word{#}]])/",
+ '/(?[[[:digit: ])/' => "Unmatched '[' in POSIX class {#} m/(?[[[:digit:{#} ])/",
+ '/(?[[:digit: ])/' => "Unmatched '[' in POSIX class {#} m/(?[[:digit:{#} ])/",
+ '/(?[[[::]]])/' => "POSIX class [::] unknown {#} m/(?[[[::]{#}]])/",
+ '/(?[[[:w:]]])/' => "POSIX class [:w:] unknown {#} m/(?[[[:w:]{#}]])/",
+ '/(?[[:w:]])/' => "POSIX class [:w:] unknown {#} m/(?[[:w:]{#}])/",
+ '/(?[a])/' => 'Unexpected character {#} m/(?[a{#}])/',
+ '/(?[\t])/l' => '(?[...]) not valid in locale {#} m/(?[{#}\t])/',
+ '/(?[ + \t ])/' => 'Unexpected binary operator \'+\' with no preceding operand {#} m/(?[ +{#} \t ])/',
+ '/(?[ \cK - ( + \t ) ])/' => 'Unexpected binary operator \'+\' with no preceding operand {#} m/(?[ \cK - ( +{#} \t ) ])/',
+ '/(?[ \cK ( \t ) ])/' => 'Unexpected \'(\' with no preceding operator {#} m/(?[ \cK ({#} \t ) ])/',
+ '/(?[ \cK \t ])/' => 'Operand with no preceding operator {#} m/(?[ \cK \t{#} ])/',
+ '/(?[ \0004 ])/' => 'Need exactly 3 octal digits {#} m/(?[ \0004 {#}])/',
+ '/(?[ \05 ])/' => 'Need exactly 3 octal digits {#} m/(?[ \05 {#}])/',
+ '/(?[ \o{1038} ])/' => 'Non-octal character {#} m/(?[ \o{1038{#}} ])/',
+ '/(?[ \o{} ])/' => 'Number with no digits {#} m/(?[ \o{}{#} ])/',
+ '/(?[ \x{defg} ])/' => 'Non-hex character {#} m/(?[ \x{defg{#}} ])/',
+ '/(?[ \xabcdef ])/' => 'Use \\x{...} for more than two hex characters {#} m/(?[ \xabc{#}def ])/',
+ '/(?[ \x{} ])/' => 'Number with no digits {#} m/(?[ \x{}{#} ])/',
+ '/(?[ \cK + ) ])/' => 'Unexpected \')\' {#} m/(?[ \cK + ){#} ])/',
+ '/(?[ \cK + ])/' => 'Incomplete expression within \'(?[ ])\' {#} m/(?[ \cK + {#}])/',
+ '/(?[ \p{foo} ])/' => 'Property \'foo\' is unknown {#} m/(?[ \p{foo}{#} ])/',
+ '/(?[ \p{ foo = bar } ])/' => 'Property \'foo = bar\' is unknown {#} m/(?[ \p{ foo = bar }{#} ])/',
+ '/(?[ \8 ])/' => 'Unrecognized escape \8 in character class {#} m/(?[ \8{#} ])/',
+ '/(?[ \t ]/' => 'Syntax error in (?[...]) in regex m/(?[ \t ]/',
+ '/(?[ [ \t ]/' => 'Syntax error in (?[...]) in regex m/(?[ [ \t ]/',
+ '/(?[ \t ] ]/' => 'Syntax error in (?[...]) in regex m/(?[ \t ] ]/',
+ '/(?[ [ ] ]/' => 'Syntax error in (?[...]) in regex m/(?[ [ ] ]/',
+ '/(?[ \t + \e # This was supposed to be a comment ])/' => 'Syntax error in (?[...]) in regex m/(?[ \t + \e # This was supposed to be a comment ])/',
+ '/(?[ ])/' => 'Incomplete expression within \'(?[ ])\' {#} m/(?[ {#}])/',
+ 'm/(?[[a-\d]])/' => 'False [] range "a-\d" {#} m/(?[[a-\d{#}]])/',
+ 'm/(?[[\w-x]])/' => 'False [] range "\w-" {#} m/(?[[\w-{#}x]])/',
+ 'm/(?[[a-\pM]])/' => 'False [] range "a-\pM" {#} m/(?[[a-\pM{#}]])/',
+ 'm/(?[[\pM-x]])/' => 'False [] range "\pM-" {#} m/(?[[\pM-{#}x]])/',
+ 'm/(?[[\N{LATIN CAPITAL LETTER A WITH MACRON AND GRAVE}]])/' => '\N{} in character class restricted to one character {#} m/(?[[\N{U+100.300{#}}]])/',
+ 'm/(?[ \p{Digit} & (?(?[ \p{Thai} | \p{Lao} ]))])/' => 'Sequence (?(...) not recognized {#} m/(?[ \p{Digit} & (?({#}?[ \p{Thai} | \p{Lao} ]))])/',
+ 'm/(?[ \p{Digit} & (?:(?[ \p{Thai} | \p{Lao} ]))])/' => 'Expecting \'(?flags:(?[...\' {#} m/(?[ \p{Digit} & (?{#}:(?[ \p{Thai} | \p{Lao} ]))])/',
+ 'm/\o{/' => 'Missing right brace on \o{ {#} m/\o{{#}/',
+ 'm/\o/' => 'Missing braces on \o{} {#} m/\o{#}/',
+ 'm/\o{}/' => 'Number with no digits {#} m/\o{}{#}/',
+ 'm/[\o{]/' => 'Missing right brace on \o{ {#} m/[\o{{#}]/',
+ 'm/[\o]/' => 'Missing braces on \o{} {#} m/[\o{#}]/',
+ 'm/[\o{}]/' => 'Number with no digits {#} m/[\o{}{#}]/',
+ 'm/(?^-i:foo)/' => 'Sequence (?^-...) not recognized {#} m/(?^-{#}i:foo)/',