Hi Ludovic!

Sorry I couldn't reply before!

ludo@gnu.org (Ludovic Courtès) writes:

> Hi Maxim,
>
> Maxim Cournoyer <maxim.cournoyer@gmail.com> skribis:
>
>> Unfortunately some of the simplifications you made appear to break it
>> :). I've tried your reworked patch and got the same result as you (no
>> result found except when using man -K). When I use the original patch it
>> works as I originally described.
>
> Oops.
>
>>> +        (define (populate-manpages-collection-dir entries)
>>> +          (let ((manpages (append-map find-files entries)))
>>> +            (for-each (lambda (manpage)
>>> +                        (let* ((dest-file (string-append
>>> +                                           manpages-collection-dir "/"
>>> +                                           (strip-store-file-name manpage))))
>>
>> Unfortunately we cannot simply use strip-store-file-name, since what
>> mandb expects to find in our manpages-collection-dir is a collection of
>> subdirectories such as man1, man3, man7, etc. such as would be found
>> under "/usr/share/man" on a traditional distro. This change instead
>> makes it look like:
>>
>> bazaar-2.7.0/          gdbm-1.12/              libxau-1.0.8/  ...
>>
>> I guess this is what broke it.
>
> Oh, got it.
>
> However, with this version of the patch, I get:
>
>    ?: 0 [+ #f 11]
>
> ERROR: In procedure +:
> ERROR: In procedure +: Wrong type argument in position 1: #f
> builder for `/gnu/store/y754cn7f468yc1b0pc13cxk99fmnwwx1-manual-database.drv' failed with exit code 1
>
> which I think is because (string-contains manpage-path "/share/man/")
> returns #f.
>
> Could you look into it?
>
> (BTW, I find it slightly clearer to use ‘string-drop’ etc. instead of
> ‘substring’.)
>

Done.

> Other than that it should be fine.

Unfortunately I cannot reproduce the problem on my side, although you seem to be
right that this is caused by the `string-contains` not matching
"/share/man/" in the manpage-path and returning #f...

The only reason I'd suspect this could happen was if the `find-files`
method (used io list all the files contained under
"$manifest-inputs/share/man/") somehow returned bogus paths (I saw that
this function has a "fail-on-error?" argument which is disabled by default).

To help further troubleshoot this, could you please use the provided
patch instead, where I inserted:

 
         (define (get-manpage-tail-path manpage-path)
           (let ((index (string-contains manpage-path "/share/man/")))
+            (unless index
+              (error "Manual path doesn't contain \"/share/man/\":"
+                     manpage-path))
             (substring manpage-path (+ index (string-length "/share/man/")))))
 
         (define (populate-manpages-collection-dir entries)

to print the unexpectedly formed manpage-path.

Thanks! I hope we can sort this out.

Maxim