Multi-stage docker

Question

I am new to docker. I have run the second image which requires a dependency "cmdstan". Therefore I want to build a two-stage docker image. I am trying to build a two-stage docker image with the first stage as follows:

FROM debian:buster


WORKDIR /cmdstan

RUN apt-get update
RUN apt-get install --no-install-recommends -qq wget ca-certificates make g++

RUN wget --progress=dot:mega https://github.com/stan-dev/cmdstan/releases/download/v2.27.0/cmdstan-2.27.0.tar.gz
RUN tar -zxpf cmdstan-2.27.0.tar.gz
RUN ln -s cmdstan-2.27.0 cmdstan
RUN cd cmdstan; make build

RUN cd cmdstan; echo "CmdStan home directory is" $PWD

ENV NAME cmdstan-docker

And I want to build a 2nd stage image with the following codes:

FROM rocker/verse:latest

RUN apt-get update \
&& apt-get install -y --no-install-recommends apt-utils ed libnlopt-dev libgdal-dev libudunits2-dev cargo jags libcairo2-dev libxt-dev libgeos-dev \
&& apt-get clean \
&& rm -rf /var/lib/apt/lists/

# Install rstan
RUN install2.r --error --deps TRUE \
rstan \
&& rm -rf /tmp/downloaded_packages/ /tmp/*.rds

# Global site-wide config -- neeeded for building packages
RUN mkdir -p $HOME/.R/ \
&& echo "CXXFLAGS=-O3 -mtune=native -march=native -Wno-unused-variable -Wno-unused-function -flto -ffat-lto-objects  -Wno-unused-local-typedefs \n" >> $HOME/.R/Makevars

# Config for rstudio user
RUN mkdir -p $HOME/.R/ \
&& echo "CXXFLAGS=-O3 -mtune=native -march=native -Wno-unused-variable -Wno-unused-function -flto -ffat-lto-objects  -Wno-unused-local-typedefs -Wno-ignored-attributes -Wno-deprecated-declarations\n" >> $HOME/.R/Makevars \
&& echo "rstan::rstan_options(auto_write = TRUE)\n" >> /home/rstudio/.Rprofile \
&& echo "options(mc.cores = parallel::detectCores())\n" >> /home/rstudio/.Rprofile

# Install rstan
RUN install2.r --error --deps TRUE \
rstan \
loo \
bayesplot \
rstanarm \
rstantools \
shinystan \
ggmcmc \
tidybayes \
LaplacesDemon \
&& rm -rf /tmp/downloaded_packages/ /tmp/*.rds

RUN install2.r --error --deps TRUE \
zoo  \
mgcv \
lubridate \
stringr  \
loo \
jsonlite \
scales \
directlabels \
betareg \
extrafont \
pointdensityP \
&& rm -rf /tmp/downloaded_packages/ /tmp/*.rds

# Install Roboto condensed
RUN wget -O /tmp/rc.zip https://fonts.google.com/download?family=Roboto%20Condensed \
&& cd /usr/share/fonts \
&& sudo mkdir googlefonts \
&& cd googlefonts \
&& sudo unzip -d . /tmp/rc.zip \
&& sudo chmod -R --reference=/usr/share/fonts/truetype /usr/share/fonts/googlefonts \
&& sudo fc-cache -fv \
&& rm -rf /tmp/rc.zip \
&& Rscript --slave --no-save --no-restore-history -e "extrafont::font_import(prompt=FALSE)"

I am wondering how I can put these two into one docker file? Really appreciate all the suggestions, thanks a lot.