Problem building rmarkdown vignettes with child

Hello,

This is a problem I posted about already some time ago:
https://stat.ethz.ch/pipermail/r-devel/2018-September/076786.html

Finally, I did had some time to create a minimal package to reproduce
the problem that vignettes with child can not be build.
https://github.com/wolski/RmarkdownVignetteProblem

The problem basically is that while all the vignettes can be build by running

devtools::build_vignettes
or
rmarkdown::render

they will all fail to build when running
devtools::build()
or
R CMD build

except of the
ABVignetteWithLocalChild.Rmd
for which I did apply the workaround suggested by  Duncan in this github issue:
https://github.com/yihui/knitr/issues/1540


Best regards
Witek

Witold Eryk Wolski