Listing 17-17 missing red symbol (code does not compile)

[ostkamp]

URL to the section(s) of the book with this problem:

https://doc.rust-lang.org/book/ch17-03-more-futures.html

book/src/ch17-03-more-futures.md

Line 107 in 90ea905

```rust,ignore,does_not_compile

Description of the problem:

There seems to be a rendering bug with listing 17-17 on the page.

The red symbol indicating that this code does not compile does not show up on the page unless the mouse is hovering over the entry.

Without mouse hovering over the entry:

With mouse:

This is not the case for other listings, for example 17-16 where it shows up permanently without mouse hovering over the entry. Only the other 2 symbols are hidden until mouse hover is done in 17-16.

Suggested fix:

I don´t know whether the behavior would change if the snippet contained more lines. If yes, then probably an empty or comment line could be added.

[chriskrycho]

Thanks for the report. It’s not really a rendering bug—it has worked this way basically “as intended” for years—, but there was definitely room for improvement here, so I opened #4280 to make it work more along the lines folks may have expected.