R devel - Jan 2006 - help.start() and Debian packaging (PR#8483)

Full_Name: Greg Kochanski
Version: 2.2.0
OS: Debian Linux on i686
Submission from: (NULL) (212.159.16.190)


Debian packages the R documentation separately from the R core code.
Consequently, it is possible for people to have R without
the HTML documentation.   (In fact, the docs are not installed by default,
so it's very likely.)


Thus, help.start() cannot depend on the HTML documentation being there.
It should check for one (or a few) files and produce some reasonable
error message if it is not there.   Maybe something like
"Warning: the HTML documentation is not installed."

Alternatively, help.start() could produce references to some on-line
HTML documentation, instead of local documentation.



A related bug is that if one calls
help.start()  when the HTML documentation does not exist,
all future calls to help() will lead to errors.

This is all based on a false premise: that a partial install of Debian
files is 'R'.

R's own scripts do always install the HTML documentation, so help.start() 
is entitled to assume that it is present.  (That is under Unix-alikes: R 
for Windows allows Compiled HTML rather than HTML, and so help.start makes 
appropriate tests).

Note that your version of 'R' is not current.

If there is a bug here, it is in the Debian re-packaging.  I trust the 
Debian packages do contain a bug reporting address other than this one: 
please use the correct one.  (The other binary distributions that I am 
aware of, e.g. RPMs, do seem to include all of R.)

On Sat, 14 Jan 2006 greg.kochanski at phonetics.oxford.ac.uk wrote:
> Full_Name: Greg Kochanski
> Version: 2.2.0
> OS: Debian Linux on i686
> Submission from: (NULL) (212.159.16.190)
>
>
> Debian packages the R documentation separately from the R core code.
> Consequently, it is possible for people to have R without
> the HTML documentation.   (In fact, the docs are not installed by default,
> so it's very likely.)
>
>
> Thus, help.start() cannot depend on the HTML documentation being there.
> It should check for one (or a few) files and produce some reasonable
> error message if it is not there.   Maybe something like
> "Warning: the HTML documentation is not installed."
>
> Alternatively, help.start() could produce references to some on-line
> HTML documentation, instead of local documentation.
>
>
>
> A related bug is that if one calls
> help.start()  when the HTML documentation does not exist,
> all future calls to help() will lead to errors.
Working as documented is not a bug.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

While I agree with you, I find that the Debian packager does not.
I already reported the problem to Debian, and they said that
enough people want light-weight installations that they will
continue splitting R into several parts.
The package maintainer is  Dirk Eddelbuettel <edd at debian.org>,
and the relevant bug report is 348051.

His response was this:
| > Ok, that confirms that all you need to do is to install r-doc-html. 
No bug,
| > it is designed this way.


Consequently, I can only appeal to your humanity and
to good programming practice.

It is good programming practice to protect the user from
his/her own mistakes, even if those mistakes are made
easier/encouraged by Debian.   It is also good programming
practice to provide appropriate error messages when something
goes wrong, even if it "shouldn't" ever go wrong.

So, yeah, you can make an argument that you don't have to
do it, but R will be a better piece of software if you make
the change.


Prof Brian Ripley wrote:
> This is all based on a false premise: that a partial install of Debian
> files is 'R'.
> 
> R's own scripts do always install the HTML documentation, so 
> help.start() is entitled to assume that it is present. ...
> 
> Note that your version of 'R' is not current.
> 
> If there is a bug here, it is in the Debian re-packaging.  I trust the 
> Debian packages do contain a bug reporting address other than this one: 
> please use the correct one.  (The other binary distributions that I am 
> aware of, e.g. RPMs, do seem to include all of R.)
> 
> On Sat, 14 Jan 2006 greg.kochanski at phonetics.oxford.ac.uk wrote:
> 
>> Full_Name: Greg Kochanski
>> Version: 2.2.0
>> OS: Debian Linux on i686
>> Submission from: (NULL) (212.159.16.190)
>>
>>
>> Debian packages the R documentation separately from the R core code.
>> Consequently, it is possible for people to have R without
>> the HTML documentation.   (In fact, the docs are not installed by 
>> default,
>> so it's very likely.)
>>
>>
>> Thus, help.start() cannot depend on the HTML documentation being there.
>> It should check for one (or a few) files and produce some reasonable
>> error message if it is not there.   Maybe something like
>> "Warning: the HTML documentation is not installed."
>>
>> Alternatively, help.start() could produce references to some on-line
>> HTML documentation, instead of local documentation.
>>
>>
>>
>> A related bug is that if one calls
>> help.start()  when the HTML documentation does not exist,
>> all future calls to help() will lead to errors.
> 
> 
> Working as documented is not a bug.
>