Install a local R package with dependencies from CRAN mirror

I have built an R package, i.e. I have the mypackage.tar.gz file. This package depends on several other packages, all downloadable and installable from any CRAN mirror.

Now I want to install this package on a system where the dependencies are not yet installed, and I would like that the dependencies will be downloaded and installed automatically when I install my package.

I tried:

install.packages("mypackage.tar.gz",type="source",dependencies=TRUE,repos="http://a.cran.mirror")

but it searches for mypackage.tar.gz on the mirror (and obviously it does not find), while if I set repos=NULL it correctly tries to install the local package file (as documented), but obviously it does not find the dependencies packages.

So my question is: is there a way to perform a 'mixed' installation (local package with online dependencies) or the only way to do is to manually install all the dependencies?

You could use install from the devtools package. Just run install("<directory of your package>", dependencies = TRUE). Its help states:

Uses R CMD INSTALL to install the package. Will also try to install dependencies of the package from CRAN, if they're not already installed.

If you already have installed your local package, you should be able to use a couple functions in tools to install the dependencies from CRAN:

library('tools')
installFoundDepends(pkgDepends('mypackage', local = FALSE)$Found)

Note: You can pass args (like repos) through installFoundDepends to install.packages.

You can also use the Depends element from the pkgDepends output to pass directly to install.packages:

install.packages(pkgDepends('mypackage')$Depends)

UPDATE: Apparently it is not possible to install a local package with dependencies=FALSE. This seems odd, since you can do that for a remote package from a repository. The reason (looking at the source code) is that if(is.null(repos) & missing(contriburl)), installation is handled via system calls to R CMD INSTALL, which has no dependency-related arguments.

Here, I'm using untar() with devtools::install() and passing in a directory to which the source tarball has been extracted.

d <- tempdir()
untar("mypackage.tar.gz", compressed="gzip", exdir=d)
devtools::install(file.path(d, "mypackage"), dependencies=TRUE,
                  repos="https://cloud.r-project.org/")

If you want to install from multiple repos, you can provide a list of them. For example, to use both Bioconductor and CRAN, you could run:

 devtools::install(file.path(d, "mypackage"), dependencies=TRUE,
                   repos=BiocManager::repositories())

NOTE: I can't figure out how to directly pass the tarball to install(), but this solution works in the meantime and leaves no clutter because we extract to a temp directory. It seems install_local() should be able to take a tarball, but I am getting an error when attempting to do so.