Name of the lexer
Rust

Code sample
A sample of the code that produces the bug.

const REQUEST: &[u8] = b"GET http://example.com/ HTTP/1.1\r\n\
    Host: example.com\r\n\
    Accept: */*\r\n\
    \r\n";

It also helps if you can provide a link to a code sample on rouge.jneen.net.

Additional context
The REQUEST is a valid Rust string literal, as described in The Rust Reference, backslash at the end of line has special meaning in Rust.