[R-pkg-devel] Rcpp: how best to include source from another Github repository

On 21 January 2025 at 12:04, Jonathan Berrisch wrote:
| first of all: I'm not an expert on this and don't really know if there
| is a recommended way.
|
| However, you may look at my 'rcpptimer' package and how it includes
| 'cpptimer' as a submodule.
|
| You can find the repository here: https://github.com/BerriJ/rcpptimer

I had written a longer (private) email to John expressing the view that git
submodules "were once more 'en vogue'" but one sees them less these days.
One reason is that they break some (somewhat standard) workflows, see
below.

Overall, this is "no win" situation. You can include the files in the
package
as a copy [2] enlarging the package, build process, etc but arguably making
it more robust, or you can keep it external which is cleaner -- but harder
as
you now have to ensure users (and CRAN !) can get / have that library.

So it is all tradeoffs one has to make.

Dirk


[1] Log from a standard r2u Ubuntu container, `git` and `ssh` added as
needed:

root at 4163d5544547:/# installGithub.r https://github.com/BerriJ/rcpptimer
Downloading GitHub repo BerriJ/rcpptimer at HEAD
'/usr/bin/git' clone --depth 1 --no-hardlinks --recurse-submodules
git at github.com:BerriJ/cpptimer.git
/tmp/remotes257564d64e0/BerriJ-rcpptimer-35ca024/inst/include/cpptimer
Cloning into
'/tmp/remotes257564d64e0/BerriJ-rcpptimer-35ca024/inst/include/cpptimer'...
The authenticity of host 'github.com (140.82.113.3)' can't be established.
ED25519 key fingerprint is
SHA256:+DiY3wvvV6TuJJhbpZisF/zLDA0zPMSvHdkr4UvCOqU.
This key is not known by any other names.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added 'github.com' (ED25519) to the list of known
hosts.
git at github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
Error: Failed to install 'rcpptimer' from GitHub:
  Command failed (128)
In addition: Warning message:
In system(full, intern = TRUE, ignore.stderr = quiet) :
  running command ''/usr/bin/git' clone --depth 1 --no-hardlinks
--recurse-submodules git at github.com:BerriJ/cpptimer.git
/tmp/remotes257564d64e0/BerriJ-rcpptimer-35ca024/inst/include/cpptimer' had
status 128 and error message 'Function not implemented'
root at 4163d5544547:/#
exit


[2] The "Rcpp-library" vignette John refers to also mentions (IIRC) that
this
is preferable for smaller libraries; its 'corels' example fits that
description.  These days other authors also vendor entire applications such
as whole SQL engines: ?\_(?)_/?  I just updated qlcal on CRAN, it
explicitly
copies the calendaring (subset) from QuantLib as I learned over 20 years
that
users have difficulties with that large library. Tradeoffs.

--
dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org