The text is calculated via cli_text(), so all cli features can be
used here, including progress variables.
cli_progress_output(text, id = NULL, .envir = parent.frame())TRUE, always.
Text to output. It is formatted via cli_text().
Progress bar id. The default is the current progress bar.
Environment to use for glue interpolation of text.
The text is passed to the progress handler(s), that may or may not be able to print it.
fun <- function() {
  cli_alert_info("Before the progress bar")
  cli_progress_bar("Calculating", total = 100)
  for (i in 1:50) {
    Sys.sleep(4/100)
    cli_progress_update()
  }
  cli_progress_output("Already half way!")
  for (i in 1:50) {
    Sys.sleep(4/100)
    cli_progress_update()
  }
  cli_alert_info("All done")
}
fun()
This function supports inline markup.
Other progress bar functions: 
cli_progress_along(),
cli_progress_bar(),
cli_progress_builtin_handlers(),
cli_progress_message(),
cli_progress_num(),
cli_progress_step(),
cli_progress_styles(),
progress-variables
Other functions supporting inline markup: 
cli_abort(),
cli_alert(),
cli_blockquote(),
cli_bullets_raw(),
cli_bullets(),
cli_dl(),
cli_h1(),
cli_li(),
cli_ol(),
cli_process_start(),
cli_progress_along(),
cli_progress_bar(),
cli_progress_message(),
cli_progress_step(),
cli_rule,
cli_status_update(),
cli_status(),
cli_text(),
cli_ul(),
format_error(),
format_inline()