[R-pkg-devel] About a need for hooks from R CMD ... commands, and a question

[Iñaki Ucar]

On Fri, 4 Jan 2019 at 19:42, Dirk Eddelbuettel <edd using debian.org> wrote:
>
>
> On 4 January 2019 at 19:24, Iñaki Ucar wrote:
> | On Fri, 4 Jan 2019 at 16:43, Dirk Eddelbuettel <edd using debian.org> wrote:
> | >
> | >
> | > For a few years now I had mused about how nice it would be to have other
> | > scripts triggered like `cleanup`.  For Rcpp, it would be nice to run
> | > compileAttributes(). For roxygen2, it would be nice to run roxygenize()
> | > (especially if that continued to work the way it did, but I digress).
> | > That was mostly a "wouldn't it be nice" question and not that urgent as I
> | > wrote myself littler scripts for most tasks anyway.
> | >
> | > But I now have a related problem at work. We are authoring C++ libraries and
> | > R packages 'mono-repo' style. And I need to reference builds of the R
> | > packages back to the repo branches / repo directories used where R CMD build
> | > ran in a branch -- in order to at R CMD INSTALL time access the matching
> | > header files and libraries from that branch.  I do not see an obvious way of
> | > encoding this in the .tar.gz created by the R CMD build step. The best I can
> | > think of is creating binaries via R CMD INSTALL --build instead of creating
> | > source tarballs.
> | >
> | > Is there something better I am missing? Any hacks, hints, or ideas?
> |
> | I'm not sure whether I understand correctly what you are trying to
> | achieve. Isn't generating a custom configure script enough for your
> | needs?
>
> That is what I thought yesterday when I wrote / updated and tested those.
> They work great when you install from source as they have access to shell's
> ${PWD} and R's getwd().
>
> But when you run R CMD build, (essentially) just cleanup and a tar are
> running. No other code. Hence my Subject: here -- a need for a hook.
>
> Once you have built a .tar.gz and run R CMD INSTALL on it, R goes off to
> _another temporary directory_ and while configure may be running ... you are
> no longer in the directory you called it from. So I have now lost the
> connection to the particular variant of headers and libraries I may have had
> in that branch.
>
> Doing R CMD INSTALL --build ... is a workaround.  But it still would be nice
> to have an explicit hook.
>
> Hope this explains it better, and thanks for the follow-up.

I see. Then I suggest the following hack (not tested). If the package
has a vignette, put there a hidden chunk that generates a file with
info about the branch and the path. This file will be available for
your configure script, which runs at INSTALL time. There you can,
e.g., retrieve that branch from a remote repo.

Iñaki