### Bug description

Is it currently possible to get quarto to error on broken links, instead of just warning about them, even if this is opt-in? Having it exit successfully when there are broken cross-links like this makes it harder to include quarto in automated workflows. Especially if multiple people are working on a site, it can mean that these breakages go unnoticed.

Related: https://github.com/r-lib/urlchecker/issues/27

even if it doesn’t error, it would be super useful to print all the broken links at the very end of building a book

### Checklist

- [ ] Please include a minimal, fully reproducible example in a single .qmd file? Please provide the whole file rather than the snippet you believe is causing the issue.
- [ ] Please [format your issue](https://quarto.org/bug-reports.html#formatting-make-githubs-markdown-work-for-us) so it is easier for us to read the bug report.
- [ ] Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
- [ ] Please document the operating system you're running. If on Linux, please provide the specific distribution.
cscheid
2022-09-29T12:30:47Z
allenmanning
enhancement
v1.4
open
Quarto should error or warn on broken links
https://github.com/quarto-dev/quarto-cli/issues/2665