[R] What happened to Canada?

Rolf Turner r.turner at auckland.ac.nz
Mon Nov 2 23:36:37 CET 2015

On 03/11/15 01:41, Marc Schwartz wrote:

>> On Nov 2, 2015, at 6:00 AM, John Kane <jrkrideau at inbox.com> wrote:
>> A rather silly question but I went to install a new package this
>> morning and as usual a list of CRAN mirrors appeared but the
>> Canadian ones had disappeared.
>> Is this some peculiarity of my system (Ubuntu 14.10 with R version
>> 3.2.2)  or a new policy for R?
>> John Kane Kingston ON Canada
> Hi John,
> Presuming that the CRAN mirror list online is current, there do not
> appear to be any CRAN mirrors in Canada which support secure HTTP
> (HTTPS), which is now the default in 3.2.2.
> See the announcement from August 14 (SIGNIFICANT USER-VISIBLE CHANGES
> https://stat.ethz.ch/pipermail/r-announce/2015/000589.html
> See ?chooseCRANmirror for more information.
> When you get a list of mirrors to select, by default the top of the
> list will include mirrors that support HTTPS. The last entry on the
> list should be (HTTP mirrors). Click that and it will bring up a list
> of additional mirrors, including Canadian locations, that support

Out of idle curiosity I started playing around with this stuff and ran 
into a puzzling phenomenon.

When I execute


I get an error message:

> Error in download.file(url, destfile = f, quiet = TRUE) :
>   unsupported URL scheme

Nevertheless a menu appears, with "(HTTP mirrors)" at the bottom, just 
as you said.

I don't understand why chooseCRANmirror() still works despite the error 
being thrown.

Tracing through what chooseCRANmirror() does I reduced the problem to:

     u <- "https://cran.r-project.org/CRAN_mirrors.csv"

which throws the error

> Error in download.file(u, destfile = "junk") : unsupported URL scheme

If I replace the "https" in the url by "http" then things run without an 
error being thrown.

There is no immediate problem for me, since I can install packages from 
CRAN OK, using my usual New Zealand mirror (which is an http mirror).

If I try to use one of the https mirrors that are shown by 
chooseCRANmirror() (e.g. Austria) then I get a warning:

> Warning: unable to access index for repository
> https://cran.r-project.org/src/contrib

and the install goes back to using the New Zealand mirror.

So there seems to be something not quite right with my system or with my 
installation of R.  Although, as I said, there is no immediate problem, 
the fact that something is not quite right worries me.

Can you (Marc) or anyone else suggest what might be the problem and how 
to fix it, or at least track it down a bit more explicitly?

Here's my

 > sessionInfo()
R version 3.2.2 (2015-08-14)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Fedora 17 (Beefy Miracle)

  [1] LC_CTYPE=en_NZ.utf8       LC_NUMERIC=C
  [3] LC_TIME=en_NZ.utf8        LC_COLLATE=en_NZ.utf8
  [5] LC_MONETARY=en_NZ.utf8    LC_MESSAGES=en_NZ.utf8
  [7] LC_PAPER=en_NZ.utf8       LC_NAME=C
  [9] LC_ADDRESS=C              LC_TELEPHONE=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

other attached packages:
[1] misc_0.0-16

loaded via a namespace (and not attached):
  [1] deldir_0.1-9        Matrix_1.1-4        mgcv_1.8-7
  [4] abind_1.4-0         spatstat_1.43-0.007 nlme_3.1-121
  [7] grid_3.2.2          polyclip_1.3-1      lattice_0.20-33
[10] goftest_1.0-2       tensor_1.5




Technical Editor ANZJS
Department of Statistics
University of Auckland
Phone: +64-9-373-7599 ext. 88276

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