Recently, I’ve been on a bit of a
I stumbled across
set of functions, which is geared toward speeding up contributions to
community repositories. There is a wonderful
vignette titled “Pull request helpers”
that explains their usage in a real-world case study. Unfortunately, a
prerequisite for using these commands is to have the repository downloaded.
To that end, running
to obtain a local copy of the repository resulted in a dreaded error:
Error in 'git2r_clone': unsupported URL protocol
Having said this, I’ll spend the rest of the post talking about diagnosing the configuration issue and the solution.
Note: This post assumes you have a development toolchain setup and have
set the appropriate environment variables for
usethis. Before continuing,
please make sure to have read through:
usethis package provides
which helps diagnose a system’s
git configuration. This function reduces the
need to type out a lot of unstructured commands in Terminal to figure out
git situation is.
In my case, the results were:
usethis::git_sitrep() # Git config (global) # * Name: 'coatless' # * Email: 'firstname.lastname@example.org' # * Vaccinated: FALSE # usethis + git2r # * Default usethis protocol: 'ssh' # * git2r supports SSH: FALSE # * Credentials: '<usethis + git2r default behaviour>' # GitHub # * Personal access token: '<found in env var>' # * User: 'coatless' # * Name: 'coatless' # * Email(s): 'not-telling' # Repo # * Path: '/Users/coatless/Desktop/r/pkg/.git' # * Local branch -> remote tracking branch: 'master' -> 'origin/master' # GitHub pull request readiness # * origin: coatless/pkg, can push
Notice, in this case, the only issue we ran into is:
git2r supports SSH: FALSE
However, that’s what is causing the issue! In fact, it’s a problematic response
because it is a silent
usethis’s dependency. That is, when
usethis is installed
so too is
git2r. Unfortunately, the CRAN
binary version of
libssh2 disabled. As a result, the package binaries from CRAN are problematic.
Binary packages are provided as a convenience. The “binary” aspect means it has been pre-compiled from source code.
So, let’s try to install the package from source locally. Within R, packages can be installed from source by typing:
install.packages('git2r', type = 'source')
Note: This requires that a compiler is present on your system. Please see R Compiler Tools for Rcpp on macOS for help on setting up the developer environment.
Unfortunately, during the package installation, the real issue is made apparent: libssh2 is not installed on the system.
checking for libssh2... no configure: WARNING: --------------------------------------------- Unable to find the LibSSH2 library on this system. Building a version without support for SSH transport. To build with SSH support, please install: libssh2-1-dev (package on e.g. Debian and Ubuntu) libssh2-devel (package on e.g. Fedora, CentOS and RHEL) libssh2 (Homebrew package on OS X) and try again. If the LibSSH2 library is installed on your system but the git2r configuration is unable to find it, you can specify the include and lib path to LibSSH2 with: R CMD INSTALL git2r --configure-vars='LIBS=-L/path/to/libs CPPFLAGS=-I/path/to/headers' ---------------------------------------------
Do as the configuration script suggests:
libssh2 library via homebrew.
The steps are as follows:
First, open Terminal by going to
Applications/Utilities in Finder or typing
in mac’s Spotlight search Terminal.
Second, make sure
homebrew is installed with:
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
homebrew, install the
libssh2 formula by typing:
brew install libssh2
Fourth, within R type:
install.packages("git2r", type = "source", configure.vars='LIBS=-L/usr/local/Cellar/libssh2/1.9.0_1/lib' )
This will install the
git2r package with the appropriate configuration
Note: At the time of this writing, the version number is
Please replace this version number with the version number
of the library installed.
Version information may be obtained by typing into Terminal:
brew list --versions | grep libssh2