Hi,
I've already posted this as a bug here (ARROW-5614), but in case somebody from the community has experience with this maybe I can resolve it quicker here...

I'm trying to install the R package in a Debian environment (an extension of the dockerhub image from rocker/rstudio). This environment has R and RStudio installed, as well as arrow-cpp, parquet-cpp and pyarrow via conda. But when I install the R package I'm getting the 

Please use arrow::install_arrow()

message. And when I try to do that 

Error: 'install_arrow' is not an exported object from 'namespace:arrow'

The installation of the package didn't seem to throw any errors, and I've told it where to find the arrow-cpp /lib and /include folders (see ARROW-5614). 

Any idea what may be going on, and whether the package can be installed and linked against arrow as installed via conda?