error: end of regex '/' has to be followed by end of placeholder '}':
       At "{://g}"
               ^
 --> tests/fail/stable/invalid_custom_regex.rs:2:25
  |
2 |     sscanf::sscanf!("", "{://g}", str);
  |                         ^^^^^^^^

error: missing '/' to end regex:
       At "{:/}"
             ^^
 --> tests/fail/stable/invalid_custom_regex.rs:3:25
  |
3 |     sscanf::sscanf!("", "{:/}", str);
  |                         ^^^^^^

error: missing '/' to end regex:
       At "{:/"
             ^
 --> tests/fail/stable/invalid_custom_regex.rs:4:25
  |
4 |     sscanf::sscanf!("", "{:/", str);
  |                         ^^^^^

error: unexpected end of regex:
       At r"{:/\"
               ^
 --> tests/fail/stable/invalid_custom_regex.rs:6:25
  |
6 |     sscanf::sscanf!("", r"{:/\", str);
  |                         ^^^^^^^

error: unexpected end of regex:
       At "{:/\\"
              ^^
 --> tests/fail/stable/invalid_custom_regex.rs:7:25
  |
7 |     sscanf::sscanf!("", "{:/\\", str);
  |                         ^^^^^^^

error: missing '/' to end regex:
       At r"{:/\/"
              ^^^
 --> tests/fail/stable/invalid_custom_regex.rs:8:25
  |
8 |     sscanf::sscanf!("", r"{:/\/", str);
  |                         ^^^^^^^^

error: missing '/' to end regex:
       At "{:/\\/"
             ^^^^
 --> tests/fail/stable/invalid_custom_regex.rs:9:25
  |
9 |     sscanf::sscanf!("", "{:/\\/", str);
  |                         ^^^^^^^^

error: regex parse error:
           ab(ab
             ^
       error: unclosed group

       In custom Regex format option:
       At "{:/ab(ab/}"
             ^^^^^^^
  --> tests/fail/stable/invalid_custom_regex.rs:11:25
   |
11 |     sscanf::sscanf!("", "{:/ab(ab/}", str);
   |                         ^^^^^^^^^^^^

error: custom regex cannot contain capture groups '(...)'.
       Either make them non-capturing by adding '?:' after the '(' or remove/escape the '(' and ')':
       At "{:/ab()ab/}"
             ^^^^^^^^
  --> tests/fail/stable/invalid_custom_regex.rs:12:25
   |
12 |     sscanf::sscanf!("", "{:/ab()ab/}", str);
   |                         ^^^^^^^^^^^^^