Hi Guix,

here’s the second batch of R packages to give us “devtools”.  I noticed
that “git2r” contains *modified* sources of libgit2, so we cannot link
it against libgit2 itself.

The git2r README says this:

  The libgit2 library has been modified, e.g. to use the R printing and
  error routines, and to use runif instead of rand.

In other places it says that libgit2 was modified to build it as an R
package.  As I don’t know what this means I’ve submitted a bug report to
ask if linking against an external libgit2 would be possible:

  https://github.com/ropensci/git2r/issues/187

I also added a note to the package recipe stating that the package
contains modified sources of libgit2.

~~ Ricardo