[Rd] package vignettes, suggests and R CMD check

[Peter Ruckdeschel]

Dear Seth,

thanks for your promptous response,

> Peter Ruckdeschel <Peter.Ruckdeschel at uni-bayreuth.de> writes:
>> We have encountered a problem concerning a dead lock in the dependency graph:
>>
>> We have two packages A1 and A2 where A2 extends A1.
>>
>> We have one package vignette for both packages, but which should be included
>> into package A1.
>>
>> So in the "suggests" field of the DESCRIPTION file of A1 we suggest A2
>> to be able to produce the vignette at build/install time.
>>
>> On the other hand this means that A2 has to be installed before being
>> able to check A1, and A1, of course, has to be installed before being
>> able to check A2.
>>
>> How can this dead lock be resolved?
> 
> Is it really a deadlock?  You can install A1 and then A2 and at that
> point you can check either one, right?

right. Not a problem at all for us. But when submitting the package to CRAN
this is a no-go condition ...

> You might also be able to make part of the vignette in A1 conditional
> on having A2 

Sorry, I am stuck here: I do not see how you could do this; could you
help me there?

> (or, of course, consider splitting the vignette or
> merging the packages).

We thought about this, too; our reasons not to do so were:

merging the packages: our packages already have a considerable size,
and the additional features provided for in the extension packages
may not be needed by everybody;

splitting the vignette: It seemed to be a good idea for us,
(a) not to have to repeat explications in the extension packages
and (b) to draw the reader's attention to the features provided for
by the extensions.


Thank you once again
Peter