[igraph] cannot set CRAN igraph option from inside another R package

[Dr Gregory Jefferis]

Dear Gabor et al.,

I use igraph in a number of R packages that I have written for 
computational neuroanatomy. Thanks for your contributions!

igraph 1.0 introduced a new return structure (controlled by the 
return.vs.es option) that in some use cases for me can be a couple of 
orders of magnitude slower.

I see this for example when computing the neighborhood for a graph 
representing at 50,000 node neuron and it is the difference between an 
operation taking 1.2s or 72s.

So I decided to set the package option inside my package like so

  igraph_options(return.vs.es=FALSE)

However when I do this if igraph is listed as Imports: but not Depends: 
then I get the following error.

Error in assign(".igraph.pars", current, envir = env) :
  cannot change value of locked binding for '.igraph.pars'
Called from: assign(".igraph.pars", current, envir = env)

Is there any way round this? I believe this is fixed in the development 
version of igraph, but I have quite a lot of users users now and I 
cannot rely on them to compile igraph from scratch rather than use CRAN.

There is a test package with a toy example here

https://jefferis.github.io/pkgusingigraph/reference/set_igraph_option.html

With many thanks for any suggestions,

Greg.

--
Gregory Jefferis, PhD
Division of Neurobiology
MRC Laboratory of Molecular Biology
Francis Crick Avenue
Cambridge Biomedical Campus
Cambridge, CB2 OQH, UK

http://www2.mrc-lmb.cam.ac.uk/group-leaders/h-to-m/g-jefferis
http://jefferislab.org
http://flybrain.stanford.edu