[R] Installing bioconduction packages in connection with loading an R package

Martin Morgan mtmorg@n@b|oc @end|ng |rom gm@||@com
Mon Oct 12 12:10:26 CEST 2020

An alternative to setRepositories() is use of (the CRAN package) BiocManager::install("gRbase") instead of install.packages(). BiocManager installs CRAN packages as well as Bioconductor packages.

Another, more transparent, solution is to use

  install.packages("gRbase", repos = BiocManager::repositories())

where the key idea is to include Bioconductor repositories explicitly. These approaches are preferred to  setRepositories(), because of the details of the twice-yearly Bioconductor release cycle, compared to the annual R release and patch cycles.

The usual approach to your problem is to move the package to Suggests:. But then the namespace commands like Imports, and the direct use of imported package functions, is not possible; you'll need to litter your code with fully resolved functions (graph::foo() instead of foo()). Also Suggests: is usually home to packages that have a limited role to play, but that does not seem likely for RBGL etc in your package.

Also, in implementing this approach one would normally check that the package were installed, and fail with an error message telling the user how to fix the problem (e.g., by installing the package). This doesn't really sound like progress. If you instead try to automatically install the package (in .onAttach(), I guess was your plan) you'll shortly run into users who need to use arguments to install.packages() that you have not made available to them.

Your CRAN page took me quickly to your package web site and clear installation instructions; I do not think use of Bioc packages is a particular barrier to use.

Martin Morgan


On 10/11/20, 2:52 PM, "R-help on behalf of Søren Højsgaard" <r-help-bounces using r-project.org on behalf of sorenh using math.aau.dk> wrote:

    Dear all,

    My gRbase package imports functionality from the bioconductor packages graph, Rgraphviz and RBGL.

    To make installation of gRbase easy, I would like to have these bioconductor packages installed in connection with installation of gRbase, but to do so the user must use setRepositories() to make sure that R also installs packages from bioconductor.

    Having to call setRepositories causes what can perhaps be called an (unnecessary?) obstacle. Therefore I have been experimenting with deferring installation of these bioc-packages until gRbase is loaded the first time using .onAttach; please see my attempt below.

    However, if the bioc-packages are not installed I can not install gRbase so that does not seem to be a viable approach. (The bioc-packages appear as Imports: in DESCRIPTION).

    Can anyone tell if it is a futile approach and / or perhaps suggest a solution. (I would guess that there are many CRAN packages that use bioc-packages, so other people must have faced this challenge before).

    Thanks in advance.

    Best regards

    .onAttach<-function(libname, pkgname) {

        ## package startup check

        already_installed <- sapply(toinstall, function(pkg)
            requireNamespace(pkg, quietly=TRUE))

        if (any(!already_installed)){
            packageStartupMessage("Need to install the following package(s): ",
                                  toString(toinstall[!already_installed]), "\n")

        ## install if needed
            if (!requireNamespace("BiocManager", quietly=TRUE))
            BiocManager::install(toinstall[!already_installed], dependencies=TRUE)

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