charset followed by comment with code inside raises error

[bryanrasmussen]

Running the following

@charset "UTF-8";
/**{void}*/
.grid__row {
  display: block;
  width: 102.27273%;
  margin-left: -1.13636%;
  margin-right: -1.13636%;
}

with command
csscss --show-parser-errors styles.css

gives following

Had a problem parsing the css at line: 1, column: 1
Failed to match sequence (SPACE? blocks:((COMMENT / IMPORT / NESTED_RULESET / RULESET){1, }) SPACE?) at line 1 char 1.
- Expected at least 1 of COMMENT / IMPORT / NESTED_RULESET / RULESET at line 1 char 1. - Expected one of [COMMENT, IMPORT, NESTED_RULESET, RULESET] at line 1 char 1.
|- Failed to match sequence (SPACE? '/' (!'/' .){0, } '/' SPACE?) at line 1 char 1.
| - Expected "/*", but got "@c" at line 1 char 1. |- Failed to match sequence ('@' [Ii] [Mm] [Pp] [Oo] [Rr] [Tt] [^;]{1, } ';' SPACE?) at line 1 char 2. | - Failed to match [Ii] at line 1 char 2.
|- Failed to match sequence ('@' [^{}]{1, } '{' SPACE? (COMMENT / RULESET / NESTED_RULESET){1, } '}' SPACE?) at line 2 char 5.
| - Expected at least 1 of COMMENT / RULESET / NESTED_RULESET at line 2 char 5. | - Expected one of [COMMENT, RULESET, NESTED_RULESET] at line 2 char 5.
| |- Failed to match sequence (SPACE? '/' (!'/' .){0, } '/' SPACE?) at line 2 char 5.
| | - Expected "/*", but got "vo" at line 2 char 5. | |- Failed to match sequence (selector:([^{}]{1, }) '{' SPACE? properties:((MIXIN_ATTRIBUTES / COMMENT / ATTRIBUTE / BLANK_ATTRIBUTE){0, }) '}' SPACE?) at line 2 char 9. | | - Expected "{", but got "}" at line 2 char 9.
| - Failed to match sequence ('@' [^{}]{1, } '{' SPACE? (COMMENT / RULESET / NESTED_RULESET){1, } '}' SPACE?) at line 2 char 5. | - Expected "@", but got "v" at line 2 char 5.
- Failed to match sequence (selector:([^{}]{1, }) '{' SPACE? properties:((MIXIN_ATTRIBUTES / COMMENT / ATTRIBUTE / BLANK_ATTRIBUTE){0, }) '}' SPACE?) at line 2 char 5. - Expected "}", but got "v" at line 2 char 5.