Bookdown error with PDF output, even with webshot and phantomJS installed

Hi all

I have a bookdown "book" that renders fine into HTML, but with PDF I get this message:

Error: Functions that produce HTML output found in document targeting latex output.
Please change the output type of this document to HTML.

I have read that installing webshot (and phantomJS) fixes this, by taking a screenshot of the offending output.

But they are installed. For instance, I can happily use webshot to take an image of any webpage. So webshot() works.

In addition, I see this:

> is_phantomjs_installed()
[1] TRUE

So what am I doing wrong? Any help greatly appreciated.

I note a recent, similar question has gone unanswered.

BSP.

sessionInfo()
R version 4.0.2 (2020-06-22)
Platform: x86_64-apple-darwin17.0 (64-bit)
Running under: macOS Mojave 10.14.6

Matrix products: default
BLAS: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRlapack.dylib

locale:
[1] en_AU.UTF-8/en_AU.UTF-8/en_AU.UTF-8/C/en_AU.UTF-8/en_AU.UTF-8

attached base packages:
[1] stats graphics grDevices utils datasets methods base

other attached packages:
[1] webshot_0.5.2 bookdown_0.20

loaded via a namespace (and not attached):
[1] ps_1.3.3 packrat_0.5.0 digest_0.6.25 R6_2.4.1 jsonlite_1.7.0 magrittr_1.5 evaluate_0.14
[8] rlang_0.4.7 stringi_1.4.6 curl_4.3 rstudioapi_0.11 callr_3.4.3 webex_0.9.1 rmarkdown_2.3
[15] tools_4.0.2 stringr_1.4.0 processx_3.4.3 xfun_0.15 yaml_2.2.1 rsconnect_0.8.16 compiler_4.0.2
[22] askpass_1.1 htmltools_0.5.0 openssl_1.4.2 knitr_1.29

You did already 'google' with your title and saw e.g. https://github.com/hadley/r4ds/issues/296 ?
I wondered what changes you made in the yaml trying to get from the html to the pdf version? Did you add the always_allow_html: yes clause or is this outdated yet?
Is the only indication that there is something wrong the message

Error: Functions that produce HTML output found in document targeting latex output.
Please change the output type of this document to HTML.