Error(s) in re-building vignettes:
  ...
--- re-building ‘multipage.Rmd’ using rmarkdown

Quitting from multipage.Rmd:25-28 [unnamed-chunk-2]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<error/purrr_error_indexed>
Error in `map()`:
ℹ In index: 10.
Caused by error in `open.connection()`:
! cannot open the connection
---
Backtrace:
     ▆
  1. └─usedthese::used_there("https://www.quantumjitter.com/project/")
  2.   └─usedthese:::extract_usage(get_links(html, url, num_links))
  3.     ├─tidyr::extract(...)
  4.     ├─tidyr::separate_longer_delim(...)
  5.     │ └─tidyr:::check_data_frame(data)
  6.     │   └─base::is.data.frame(x)
  7.     ├─purrr::list_rbind(...)
  8.     │ └─purrr:::check_list_of_data_frames(x)
  9.     │   └─vctrs::obj_check_list(x, call = error_call)
 10.     ├─purrr::list_flatten(...)
 11.     │ └─vctrs (local) is_node(x)
 12.     └─purrr::map(...)
 13.       └─purrr:::map_("list", .x, .f, ..., .progress = .progress)
 14.         ├─purrr:::with_indexed_errors(...)
 15.         │ └─base::withCallingHandlers(...)
 16.         ├─purrr:::call_with_cleanup(...)
 17.         └─usedthese (local) .f(.x[[i]], ...)
 18.           ├─dplyr::mutate(...)
 19.           ├─rvest::html_table(html_element(read_html(x), ".usedthese"))
 20.           ├─rvest::html_element(read_html(x), ".usedthese")
 21.           ├─xml2::read_html(x)
 22.           └─xml2:::read_html.default(x)
 23.             ├─base::suppressWarnings(...)
 24.             │ └─base::withCallingHandlers(...)
 25.             ├─xml2::read_xml(x, encoding = encoding, ..., as_html = TRUE, options = options)
 26.             └─xml2:::read_xml.character(...)
 27.               └─xml2:::read_xml.connection(...)
 28.                 ├─base::open(x, "rb")
 29.                 └─base::open.connection(x, "rb")
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Error: processing vignette 'multipage.Rmd' failed with diagnostics:
ℹ In index: 10.
Caused by error in `open.connection()`:
! cannot open the connection
--- failed re-building ‘multipage.Rmd’

--- re-building ‘usedthese.Rmd’ using rmarkdown
--- finished re-building ‘usedthese.Rmd’

SUMMARY: processing the following file failed:
  ‘multipage.Rmd’

Error: Vignette re-building failed.
Execution halted