[igraph] What is minimum version of R that supports igraph?

[Bob Harris]

Sorry to ask such a basic question.  (And I did try to find an answer in the 
archive.)

(see log below) My attempt to install igraph on a machine running R 3.2.5 
failed.  I can't tell whether this was a failure of the mirror or whether 
igraph is not supported by R 3.2.5 -- at the end of the log there are two 
warnings.

The answer will guide my next step.  Installing a more recent version of R is a 
possibility but I expect it to be quite a headache (and which version is right? 
the list of debian versions I found reports that every version from 3.2.5 to 
3.5.0 is either "experimental" or "unstable").  So I'd like to avoid that if at 
all possible.

Thanks for any help,
V


This is what I tried:

$ R --vanilla
> install.packages(c("igraph"))

Installing package into ‘/usr/local/lib/R/site-library’
(as ‘lib’ is unspecified)
Warning in install.packages(c("igraph")) :
  'lib = "/usr/local/lib/R/site-library"' is not writable
Would you like to use a personal library instead?  (y/n) [y]

Would you like to create a personal library
~/R/x86_64-pc-linux-gnu-library/3.2
to install packages into?  (y/n) [y]

--- Please select a CRAN mirror for use in this session ---
Error in download.file(url, destfile = f, quiet = TRUE) : 
  unsupported URL scheme
HTTPS CRAN mirror 

 1: 0-Cloud [https]                2: Austria [https]             
 ......... snip .........
19: USA (TN) [https]              20: USA (TX) [https]            
21: USA (WA) [https]              22: (HTTP mirrors)              

Selection: [19]

Warning: unable to access index for repository 
https://mirrors.nics.utk.edu/cran/src/contrib:
  unsupported URL scheme
Warning message:
package ‘igraph’ is not available (for R version 3.2.5)