[This article was first published on Achim Zeileis, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)Want to share your content on R-bloggers? click here if you have a blog, or here if you don't. After 20 years of service the R-Forge package hosting platform will be retiring soon. Codeberg is a modern alternative that shares many of the ideas and values that R-Forge was built on. A tutorial for transitioning to Codeberg (or other Git-based platforms) is provided. You say goodbyeR-Forge was created 20 years ago after the2nd useR! conference in 2006.Kurt Hornik had the idea that“R should have its own SourceForge!” (note that GitHub did not yet exist at the time).However, the goal was that this code sharing platform should becreated by the R community for the R community.The implementation was led by Stefan Theussl in the following monthsusing GForge/FusionForge, a fork of the software behind SourceForge.Hosting and funding was provided by WU Wirtschaftsuniversität Wien andThe R Project.R-Forge offers a Subversion (SVN) repository for collaborative development of R packages along with various otherservices that were state of the art at the time: daily package builds and checks, forums, mailing lists, bug trackers, web pages.A short introduction was published in the inaugural issue of The R Journal:Theußl & Zeileis (2009). “Collaborative Software Development Using R-Forge.” The R Journal, 1(1):9-14.doi:10.32614/RJ-2009-007As the FusionForge system is no longer maintained, R-Forge will be retired in the next months, switching to a read-only site.The system was somewhat dated anyways: The website has a certain “00s” vibe (see the screenshot of my profile page below)and it lacks services that became standard over the last two decades like issues, pull requests, and continuous integration.I say helloCodeberg is a non-profit, community-led effort that provides services to free and open-source projects,such as Git hosting (using Forgejo), pages, continuous integration, etc.It is run by the non-profit organization Codeberg e.V. based in Berlin, Germany, which contributorscan (but do not have to) become a member of.(I joined this summer.)Thus, Codeberg shares many of the ideas and values, that R-Forge was built on, but providesstate-of-the-art open-source tools for collaborative development of R packages (and beyond).For a first impression of the look and feel, see the screenshot of my profile page below.I say go go goFor transitioning from R-Forge to Codeberg – or some other Git-based code hosting platform – Reto Stauffer has written up a step-by-step guide.The most important steps are also listed below.1. SVN checkout from R-ForgeThe starting point for the transition is the SVN repository fromR-Forge that you probably have already checked out. For illustration we are using the c403 R packagethat is one of the packages contained in the exams project on R-Forge.svn checkout svn://R-Forge.R-project.org/svnroot/exams/2. List of R-Forge contributorsTo find all SVN usernames who ever contributed to the SVN on R-Forge repository(in this example, to the folder exams/pkg/c403) the command svn log -q can be used. Using the following shell commanda text file with the unique names can be created. Note that exams/pkg/c403 needs to be replaced for other projectsand the output file name can be adjusted too:(cd exams/pkg/c403 && svn log -q | grep -e '^r' | awk 'BEGIN { FS = "|" } ; { print $2 }' | sort | uniq) > \ authors_c403.txtThis creates the text file authors_c403.txt which will look something like: azeileis retosThis file needs to be modified by adding the full names and e-mail addresses of the contributors.Important: The leading spaces need to be removed in each line for the subsequent commands to work.azeileis = Achim Zeileis retos = Reto Stauffer Provided the profile pages on R-Forge are up to date for the users, it is also possible to scrapethis information, see the optional step 2*. below.3. Clone a Git version of the SVNUsing git-svn a Git version of the SVN can be easily created.For this step it is crucial that all users are listed in the authors file created in the previousstep, otherwise git-svn will fail.git svn clone svn://R-Forge.R-project.org/svnroot/exams/pkg/c403 \ --authors-file=authors_c403.txt --no-metadata \ git-c403Again, adjust the URL of the SVN, the authors file name, and the name of the git repository (git-c403)as needed.4. Optional: Filter files in the Git repositoryThis step is not needed for the c403 example but is particularly useful when migrating a fullR-Forge repository (rather than just a pkg sub-folder). In that caseit might be useful to filter out certain files or directories such as the initial README fileauto-created by R-Forge or the www sub-directory (typically just containing original PHP file ora auto-generated web page from pkgdown or altdoc).Such files can be filtered, i.e., erased completely from the repository history, using git-filter-repo:git-filter-repo --force --path 'README' --invert-pathsgit-filter-repo --force --path 'www' --invert-paths5. Import Git repository on CodebergFirst, create a new project on Codeberg, e.g., https://codeberg.org/zeileis/c403. The project shouldbe completely empty without any initial commit.Then, all left to do then is to tell the Git repository where its new home is (again adjust all namescorrespondingly):cd git-c403git remote add origin ssh://git@codeberg.org/zeileis/c403.gitgit push --set-upstream origin mainAnalogous commands can be used for setting the origin to a project on GitHub, GitLab, etc.All history will be immediately available in the new repository. If the authors have accounts onCodeberg, their profiles will be linked based on the e-mail address(es) associated with theirCodeberg account.6. Package builds and checks via R-universeTo automatically build and check the development versions of the R package onCodeberg, the most convenient solution is to use theR-universe servicedeveloped by Jeroen Ooms and provided by rOpenSci.In short, to make use of it, you need a GitHub account and create a repositorylike zeileis.r-universe.dev.This should contain a packages.json file with the names and repository URLsof one or more R packages, e.g.,[ { "package": "c403", "url": "https://codeberg.org/zeileis/c403" }]As a final step, the R-universe app has to be installed on the same GitHubaccount. See the R-universe set updocumentation for more details.7. Codeberg pagesIf you want to add a project page for your package, e.g., generated viaaltdoc orpkgdown, thenhttps://codeberg.page/ can be used.The c403 package does not have a page, yet, but for an example seehttps://zeileis.codeberg.page/topmodels/ which is generated fromthe topmodels R packageusing altdoc in combination with quarto.All that needs to be done to create the page manually, is to create anempty branch pages via git switch --orphan pages, adding the staticsite files, and pushing them to the repository.Alternatively, it is also possible to use Forgejo actionsto do this automatically.8. Update descriptions and linksFinally, inform users where the sources of the package can be found, i.e., updatethe DESCRIPTION (especially the URL and BugReports fields) and in the NEWS.Additionally, a README.md file would be expected in a project while on R-Forgethis was often not used (because R-Forge would be aware of the DESCRIPTION instead).Finally, it is recommended to add a link from the old R-Forge project to the newCodeberg project (possibly also in the www folder). To assure that none of thecontributors can make modifications in the old R-Forge SVN, the permissionson R-Forge can be switched to read-only (typically for the Senior Developer role).Optional addition: 2.* Scrape author names and e-mail addressesIn step 2, after the file with the author names (authors_c403.txt in the example above) has been created,one can try to automate the addition of proper names and e-mail addresses. This is particularly usefulif there are more than just a handful of users. It works when the R-Forge user pages list the proper namesand the (current) e-mail addresses.The function below can be called in R asrforge_authors("c403")It first reads the authors_c403.txt file, looks up all users on R-Forge(using the rvest package),and then updates the authors_c403.txt file accordingly.rforge_authors unlist() |> unique() if (length(n) < 1L) n lapply(as.data.frame) |> lapply(subset, subset = X1 == "Email Address:", select = "X2", drop = TRUE) |> unlist() |> unique() |> gsub(pattern = " @nospam@ ", replacement = "@", fixed = TRUE) if (length(e) < 1L) e