Why do I need SVN to install rgl from github using install_github?

Question

It was surprising to find install_github failing with a message "SVN does not seem to be installed on your system" indicating that SVN was needed. This followed the advice from a well-known rgl installation question How do I install the latest version of rgl. I could install it manually, but I did not understand the message and posted the question in the title.

After some messy investigation we found that it was due to a remote configuration line in the rgl package DESCRIPTION file that was not needed. This answer is in the comments to the answer marked correct.

However we also found that much of the guidance in the original question was out-of-date and it has since been modified.

Screen shot:

Answer 1

Edited: the Github mirror is up to date again, so all of the methods listed in How do I install the latest version of rgl? should be fine. If the server dies again, you can always use install.packages() or use SVN.

The install_github() method should no longer require an SVN install.

Answer 2

You can install from RForge and any other SVN repo using the proper SVN variant of install_github(). The devtools package has install_svn, and so do the lighter-weight alternatives such as the remotes packages.

But in all these cases you still need ... an SVN client to download from an SVN repo. Which makes some sense.

What you can do, however, using just git is to use the read-only mirror every CRAN package has on GitHub. For rgl the GitHub mirror repo is here and I would expect to be successful in using install_github against that repo.