failure value -6

[yonicd]

what does this failure mean? i have seen it a few times locally, but can't find any example online

library(leaflet)
library(htmltools)
library(webshot)

tagList(
  tags$h1( 'Leaflet Map for Screenshot' )
  ,leaflet() %>% addTiles() %>% fitBounds(0, 40, 10, 50)
) %>%
  html_print %>%
  # get forward slash on windows
  normalizePath(.,winslash="/") %>%
  # replace drive:/ with drive:// so C:/ becomes C://
  gsub(x=.,pattern = ":/",replacement="://") %>%
  # appends file:/// to make valid uri
  paste0("file://",.) %>%
  # screenshot it for lots of good reasons
  webshot( file = "stream_screen.png", delay = 3 )
#> Error in webshot(., file = "stream_screen.png", delay = 3): webshot.js returned failure value: -6

details::details(sessioninfo::session_info(),summary = 'session info')

session info

``` r ─ Session info ─────────────────────────────────────────────────────────────── setting value version R version 3.6.1 (2019-07-05) os macOS Mojave 10.14.5 system x86_64, darwin15.6.0 ui X11 language (EN) collate en_US.UTF-8 ctype en_US.UTF-8 tz America/New_York date 2020-03-04 ─ Packages ─────────────────────────────────────────────────────────────────── package * version date lib source assertthat 0.2.1 2019-03-21 [1] CRAN (R 3.6.0) backports 1.1.5 2019-10-02 [1] CRAN (R 3.6.0) callr 3.4.2 2020-02-12 [1] CRAN (R 3.6.1) cli 2.0.1 2020-01-08 [1] CRAN (R 3.6.0) clipr 0.7.0 2019-07-23 [1] CRAN (R 3.6.0) crayon 1.3.4 2017-09-16 [1] CRAN (R 3.6.0) crosstalk 1.0.0 2016-12-21 [1] CRAN (R 3.6.0) desc 1.2.0 2019-12-01 [1] Github (r-lib/desc@61205f6) details 0.2.1 2020-01-12 [1] local digest 0.6.25 2020-02-23 [1] CRAN (R 3.6.0) evaluate 0.14 2019-05-28 [1] CRAN (R 3.6.0) fansi 0.4.1 2020-01-08 [1] CRAN (R 3.6.0) fastmap 1.0.1 2019-10-08 [1] CRAN (R 3.6.0) glue 1.3.1.9000 2020-02-07 [1] Github (tidyverse/glue@7131fc3) highr 0.8 2019-03-20 [1] CRAN (R 3.6.0) htmltools * 0.4.0 2019-10-04 [1] CRAN (R 3.6.0) htmlwidgets 1.5.1 2019-10-08 [1] CRAN (R 3.6.0) httpuv 1.5.2 2019-09-11 [1] CRAN (R 3.6.0) httr 1.4.1 2019-08-05 [1] CRAN (R 3.6.0) jsonlite 1.6.1 2020-02-02 [1] CRAN (R 3.6.0) knitr 1.28 2020-02-06 [1] CRAN (R 3.6.0) later 1.0.0.9002 2020-03-03 [1] Github (r-lib/later@0fb877a) leaflet * 2.0.2 2018-08-27 [1] CRAN (R 3.6.0) magrittr 1.5 2014-11-22 [1] CRAN (R 3.6.0) mime 0.9 2020-02-04 [1] CRAN (R 3.6.0) png 0.1-7 2013-12-03 [1] CRAN (R 3.6.0) processx 3.4.2 2020-02-09 [1] CRAN (R 3.6.1) promises 1.1.0.9000 2020-03-03 [1] Github (rstudio/promises@627dfc6) ps 1.3.2 2020-02-13 [1] CRAN (R 3.6.1) R6 2.4.1 2019-11-12 [1] CRAN (R 3.6.0) Rcpp 1.0.3 2019-11-08 [1] CRAN (R 3.6.1) rlang 0.4.5 2020-03-01 [1] CRAN (R 3.6.0) rmarkdown 2.1.1 2020-01-30 [1] Github (rstudio/rmarkdown@18ba267) rprojroot 1.3-2 2018-01-03 [1] CRAN (R 3.6.0) sessioninfo 1.1.1 2018-11-05 [1] CRAN (R 3.6.0) shiny 1.4.0 2019-10-10 [1] CRAN (R 3.6.0) stringi 1.4.6 2020-02-17 [1] CRAN (R 3.6.1) stringr 1.4.0 2019-02-10 [1] CRAN (R 3.6.0) webshot * 0.5.2 2019-11-22 [1] CRAN (R 3.6.0) withr 2.1.2 2018-03-15 [1] CRAN (R 3.6.0) xfun 0.12 2020-01-13 [1] CRAN (R 3.6.0) xml2 1.2.2 2019-08-09 [1] CRAN (R 3.6.0) xtable 1.8-4 2019-04-21 [1] CRAN (R 3.6.0) yaml 2.2.1 2020-02-01 [1] CRAN (R 3.6.0) [1] /Library/Frameworks/R.framework/Versions/3.6/Resources/library ```

^{Created on 2020-03-04 by the reprex package (v0.3.0)}