error: end of regex '/' has to be followed by end of placeholder '}'
 --> tests/fail/nightly/invalid_custom_regex.rs:2:30
  |
2 |     sscanf::sscanf!("", "{://g}", str);
  |                              ^

error: missing '/' to end regex
 --> tests/fail/nightly/invalid_custom_regex.rs:3:28
  |
3 |     sscanf::sscanf!("", "{:/}", str);
  |                            ^^

error: missing '/' to end regex
 --> tests/fail/nightly/invalid_custom_regex.rs:4:28
  |
4 |     sscanf::sscanf!("", "{:/", str);
  |                            ^

error: unexpected end of regex
 --> tests/fail/nightly/invalid_custom_regex.rs:6:30
  |
6 |     sscanf::sscanf!("", r"{:/\", str);
  |                              ^

error: unexpected end of regex
 --> tests/fail/nightly/invalid_custom_regex.rs:7:29
  |
7 |     sscanf::sscanf!("", "{:/\\", str);
  |                             ^^

error: missing '/' to end regex
 --> tests/fail/nightly/invalid_custom_regex.rs:8:29
  |
8 |     sscanf::sscanf!("", r"{:/\/", str);
  |                             ^^^

error: missing '/' to end regex
 --> tests/fail/nightly/invalid_custom_regex.rs:9:28
  |
9 |     sscanf::sscanf!("", "{:/\\/", str);
  |                            ^^^^

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

       In custom Regex format option
  --> tests/fail/nightly/invalid_custom_regex.rs:11:28
   |
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 ')'
  --> tests/fail/nightly/invalid_custom_regex.rs:12:28
   |
12 |     sscanf::sscanf!("", "{:/ab()ab/}", str);
   |                            ^^^^^^^^