message: cleaner check_tz (avoid <<-)
diff: @@ -230,8 +230,10 @@ is_installed <- function(pkg) {
  check_tz <- function(timezone) {
  - tryCatch(
  - lubridate::force_tz(as.POSIXct("2021-03-01 10:40"), timezone),
  + tryCatch({
  + lubridate::force_tz(as.POSIXct("2021-03-01 10:40"), timezone)
  + timezone
  + },
  error = function(e) {
  warning(
  "Invalid time zone '", timezone, "', ",
  @@ -240,8 +242,7 @@ check_tz <- function(timezone) {
  conditionMessage(e),
  call. = FALSE
  )
  - timezone <<- "UTC"
  + "UTC"
  }
  )
  - timezone
  }
  