`rocker/verse` does not run `tcltk`

[isaactpetersen]

I am running the latest Docker image of rocker/verse on Ubuntu 20.04.2 LTS using a GitLab runner. When I try to load the package predictABEL in R 4.1.1, I receive the following error:

> library("PredictABEL")
Error: package or namespace load failed for 'PredictABEL':
.onLoad failed in loadNamespace() for 'tcltk', details:
call: dyn.load(file, DLLpath = DLLpath, ...)
error: unable to load shared object '/usr/local/lib/R/library/tcltk/libs/tcltk.so':
libtcl8.6.so: cannot open shared object file: No such file or directory

I verified that I am able to load other packages in R. I also verified that the predictABEL package is installed. The issue appears to be similar to Issue https://github.com/rocker-org/rocker-versioned/issues/141. In that issue, @cboettig noted that:

you just need the dev libraries for tcltk to work

I'm a bit new to Docker and rocker, so I'm not sure how to get the dev libraries for tcltk on the rocker image. Your help would be greatly appreciated.

[cboettig]

Correct, there are a few ways to install the required dev libraries depending on your use case.

• just use rocker/geospatial, which has the lib: https://github.com/rocker-org/rocker-versioned2/blob/master/scripts/install_geospatial.sh#L32
• If you are already writing your own Dockerfile extending a rocker image, do apt update && apt -y install tk-dev in a RUN block
• docker exec into a running container and run the apt command

[eddelbuettel]

Actually, in this case we just need the Tk runtime package. For apt: tcl, tk pulling in tcl8.6 and tk8.6.

[isaactpetersen]

Using rocker/geospatial worked well. Thanks!