[R-pkg-devel] Undeclared packages ... in Rd xrefs

[Duncan Murdoch]

On 02/02/2021 9:13 a.m., Ulrike Grömping wrote:
> Am 02.02.2021 um 02:38 schrieb Duncan Murdoch:
>> On 01/02/2021 5:03 p.m., Ulrike Grömping wrote:
>>> Dear package developeRs,
>>>
>>> under the Fedora clang checks, I find the note
>>>
>>> "Undeclared packages ‘FrF2’, ‘DoE.wrapper’, ‘sfsmisc’, ‘DoE.MIParray’,
>>> ‘planor’ in Rd xrefs"
>>>
>>> for my package DoE.base. I understand that package planor has been
>>> archived from CRAN; I don't understand what is wrong with the other
>>> xrefs; only the R-Devel Fedora clang flavor seems to complain, and I did
>>> not find an explanation in the section on cross references in Writing R
>>> Extensions. Can someone explain the meaning of this note?
>>
>> There's a line in the Writing R Extensions manual section 2.5
>> Cross-refernces for R-devel that says:
>>
>> "Packages referred to by these ‘other forms’ should be declared in the
>> DESCRIPTION file, in the ‘Depends’, ‘Imports’, ‘Suggests’ or
>> ‘Enhances’ fields."
>>
>> The other forms are the forms of links to other packages.  So
>> presumably you don't mention those packages in your DESCRIPTION file.
>> Generally that means they should be listed in Suggests, which doesn't
>> force them to be installed, but they will be installed during tests.
>> You might also argue they should be in Enhances, though that seems a
>> worse fit.
>>
>> Duncan Murdoch
> 
> 
> Thank you for the explanation! I will remove the xref to sfsmisc
> (because it does not make sense to suggest that package). The three
> other still available packages all depend on or import DoE.base. Thus,
> if I incorporate them in Suggests, I will create a circular dependence
> structure. Doesn't that create problems?

It creates small problems, not serious ones. You just need to make sure 
that a version of your package is available when those packages are 
installed for testing.  So things need to happen in something like this 
order on a totally new machine:

  - install the "hard" dependencies for your package.
  - install your package
  - install the "soft" dependencies for your package.

I just discovered that the remotes::install_deps(dependencies = TRUE) 
function can't currently do things in the right order, but 
remotes::install_local(dependencies = TRUE) is fine.  I didn't check the 
base function install.packages(dependencies = TRUE).

Duncan Murdoch