`install_github` with space in `.libPaths()[1]`

[mathematicalcoffee]

Issue was raise in this stackoverflow question -- the user is installing a package (under cygwin) using install_github, and their R library path has a space in it.

Copied the log from that question:

library(devtools)
install_github('ggbiplot','vqv')
Warning: invalid package 'Yaseen/R/win-library/2.14'
Error: ERROR: cannot cd to directory 'C:/Users/Muhammad'
Error: Command failed (1)
In addition: Warning message:
running command '"C:/PROGRA~1/R/R-214~1.2/bin/i386/R" CMD INSTALL C:\Users\MUHAMM~1\AppData\Local\Temp\Rtmpsx4n5u/ggbiplot_0.5.tar.gz --library=C:/Users/Muhammad Yaseen/R/win-library/2.14' had status 1

The problem arises because the --library=... is not quoted.

Having a (albeit very quick) look at the devtools sources, it looks like if you change install.r such that .libPaths()[1] is quoted in

R(paste("CMD INSTALL ", built_path, " --library=", .libPaths()[1], # <--
    sep = ""), tempdir())

The error might be fixed.

[hadley]

Hmmm, I wonder if I also need to quote it in system.r