[R] 3.6 on debian stretch

[Larry Martell]

I need to run 3.6 on debian stretch - I followed the instructions here:

https://cran.r-project.org/bin/linux/debian/

and I was able to install it. But 2 packages I need,  r-cran-caret and
r-cran-ggplot2 will not install:

# apt-get install r-cran-ggplot2
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 r-cran-ggplot2 : Depends: r-api-3
                  Depends: r-cran-digest but it is not going to be installed
                  Depends: r-cran-gtable (>= 0.1.1) but it is not
going to be installed
                  Depends: r-cran-plyr (>= 1.7.1) but it is not going
to be installed
                  Depends: r-cran-reshape2 but it is not going to be installed
                  Depends: r-cran-scales (>= 0.4.1) but it is not
going to be installed
                  Depends: r-cran-tibble but it is not going to be installed
                  Depends: r-cran-lazyeval but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

Is there a way to get these 2 packages for my environment?

Thanks!