useR! 2024

We report on a project where three older R packages for spatial analysis: rgdal for reading and writing vector and raster data and coordinate transfromation, rgeos for geometric transformations and predicates and maptools have been taken off CRAN on Oct 16, 2023 because their maintainer retired, and more modern approaches (e.g., sf and terra) had superseded them. To avoid a very large number of R packages that depended on one or more of these packages, directly or indirectly, being removed from CRAN, we took a number of steps. In this talk we describe the steps we took to minimize lasting damage to other packages on CRAN, and report on the lessons learnt. Over the course of the project the number of at-risk packages decreased from more than 550 to less than 100. Of the 70 or so packages still on an at-risk watch-list, about half were actively archived by their maintainers as outdated. We will discuss some key takeaways/pieces of advice for developers considering software retirement, and propose a mechanism of deprecating packages with a deprecation date, which could for instance show up as a NOTE when checking packages that use them.