bug#49452: Confusing behavior with (include) used in file in GUILE_LOAD_PATH

[Bengt Richter]

Hi Vijay,

On +2021-07-06 19:31:38 -0500, Vijay Marupudi wrote:
> Hello all,
> 
> It is unclear to me what the intended behavior for (include
> "filename.scm") is, so I'm sending an email about this potential bug.
> 
> The Local Inclusion docs
> <https://www.gnu.org/software/guile/manual/html_node/Local-Inclusion.html>
> seem to state that relative paths are found relative to the file that
> included them.
> 
> > If file-name is a relative path, it is searched for relative to the
> > path that contains the file that the include form appears in.
> 
> So if I have a file "/libraries/libname/main.scm" than has (include
> "./helpers.scm"), then the file "/libraries/libname/helpers.scm"
> *should* (I think) be imported.
>

A little nit, but
    (include "filename.scm")
is not identical to
    (include "./filename.scm")
so might it be worth trying
   (include "helpers.scm")
in your code?

And/or should the docs explain that both ways of writing a relative
file name in this context are or are not acceptable?

Might some macro dislike leading dots?

Long shot ;-)

> But this does not seem to work if "/libraries" is in the GUILE_LOAD_PATH
> and my current working directory is somewhere else, say "/home/user" and
> I'm running "/home/user/program.scm" that imports the (libname main)
> library from "/libraries". Then Guile seems to try to include the
> "libname/helpers.scm" file from the current directory, which does not
> exist.
> 
> Conversations with leoprikler in IRC have revealed to me that
> call-with-include-port is the function responsible for this behavior
> <https://git.savannah.gnu.org/cgit/guile.git/tree/module/ice-9/psyntax.scm#n3231>.
> `syntax-source` returns a file path relative to the load path, and
> include tries to use that path to open a file relative to the current
> working directory.
> 
> In Guile's bug guidelines
> <https://www.gnu.org/software/guile/docs/docs-2.2/guile-ref/Reporting-Bugs.html>,
> to me this fits
> 
> * Whenever documentation and actual behavior differ, you have certainly
>   found a bug, either in the documentation or in the program.
> 
> and potentially
> 
> * When some part of the documentation is not clear and does not make
>   sense to you even after re-reading the section, it is a bug.
> 
> I believe this is a bug, but I may be wrong, so emailing to clarify.
> Thank you!
> 
> Vijay Marupudi
> PhD Student in Human Centered-Computing
> Georgia Institute of Technology
> 
> 
> 
> 

-- 
Regards,
Bengt Richter