Workarounds

Ian Lyttle

2018-04-10

Source: vignettes/workarounds.Rmd

In the initial shakedown of this package, my colleague Emily Bosak and I found some glitches.

Too many repos

Glitch

If you are using devtools 1.13.4, and if your collection of repositories is too long, devtools::build() runs into a problem. The error looks like this:

'/Library/Frameworks/R.framework/Resources/bin/R' --no-site-file --no-environ --no-save --no-restore  \
  --quiet CMD build '/Users/ijlyttle/Documents/git/github/public_me/ghentr' --no-resave-data  \
  --no-manual 

Error: 4:3: unexpected symbol
3: "https://pages.github.schneider-electric.com/SE-AAP-R/SERAN2/"
4:   ...
     ^
Execution halted
Error: Command failed (1)

Workarounds

As suggested in the response to this issue, if you use pkgbuild::build(), used in the development version of devtools (as of early 2018), this problem goes away.

Another way to build the source package is to follow the “Build” > “More” > “Build Source Package” sequence in the RStudio IDE:

At the end of the process, the string you need for drat::insertPackage() will be printed to that window.

Windows and SSH

Frustratingly, this glitch can be as many as three separate glitches.

Glitch

This is an issue we have seen on Windows - our initial investigation confirmed this for Windows 7. Jenny Bryan (thanks!) confirmed this for Windows 10.

This appears when using usethis::use_github() or local variation of it, using SSH for the git remotes.

One of the functions that usethis::use_github() relies on is git2r::push() - the credentials argument to use_github() is passed to push(). If its value is NULL (the default), then push() will pass the request for credentials to an ssh-agent. I find that this works well on Mac, but I am having trouble to establish an ssh-agent on Windows that can make itself known to git2r.

Thus, when we tried this:

use_github()

We got this:

...
✔ Creating GitHub repository
✔ Adding GitHub remote
✔ Pushing to GitHub and setting remote tracking branch
Error in .local(object, ...) : 
  Error in 'git2r_push': error authenticating: failed connecting agent

Workaround

Luckily, there is an alternative: if use_github() cannot use the ssh-agent, we can supply the credentials argument:

use_github(credentials = git2r::cred_ssh_key())

Glitch

If you created your keys using the RStudio IDE, it will put them in "C:/Users/username/.ssh".

The function git2r::cred_ssh_key() looks for your keys in the directory "~/.ssh". On Windows, this may be problematic. When we type path.expand("~"), we get "C:/Users/username/Documents". This means that git2r::cred_ssh_key() looks for our keys in "C:/Users/username/Documents/.ssh"; they aren’t there!

Workarounds

One solution is to create a symbolic directory-link so that we need keep only one set of keys. Following the Windows “Start” button, we opened the command line, using “Run as administrator”.

At this Windows command line, we created the symbolic directory-link:

MKLINK /D "C:\Users\username\Documents\.ssh" "C:\Users\username\.ssh"

Jenny Bryan, at “Happy Git with R”, proposed another solution to tell git2r::cred_ssh_key() where to find your .ssh directory:

cred <- 
  git2r::cred_ssh_key(
    publickey = "~/../.ssh/id_rsa.pub", 
    privatekey = "~/../.ssh/id_rsa"
  )

use_github(credentials = cred)

Either way, git2r::push() can find your keys.

Glitch

If your key is protected by a passphrase (it is, right?), git2r::push() needs your help to get it.

Workaround

If the package getPass is installed, then git2r::push() will launch a popup where you can enter your (obscured) passphrase.

install.packages("getPass")

At this point, you should be able to use SSH keys on Windows without difficulty.

use_github(credentials = git2r::cred_ssh_key())