GNOME help (yelp): Unknown Error when searching

[sirgazil]

Hi,

Every time I search for something that Yelp can't find in the help 
documentation I'm seeing the following error:

  Unknown Error
  The URI ‘xref:search=SEARCH_TERM_HERE’ could not be parsed.

For example, when I tried "screencast", I got:

  Unknown Error
  The URI ‘xref:search=screencast’ could not be parsed.

I don't know what the expected behavior should be, as I don't have another 
distro around to check, but I imagine Yelp should display a page saying the 
term was not found, not an error.

I don't know if this is related, but when I start yelp from a terminal I see 
these errors:

  $ LANG=C yelp
  I/O error : Attempt to load network entity 
http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd
  I/O error : Attempt to load network entity 
http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd
  I/O error : Attempt to load network entity 
http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd

I'm using the GNU system installed with Guix, GNOME 3.28.2 and Yelp 3.28.1. 
Guix describe says:

  $ LANG=C guix describe
  Generation 4  Aug 29 2019 15:33:41    (current)
    guix 0f3624f
      repository URL: https://git.savannah.gnu.org/git/guix.git
      branch: master
      commit: 0f3624f8bc102cd729bcd887a171c5588b397c5b

I see that Guix now provides GNOME and Yelp version 3.30, but I can't upgrade 
right now. Could someone using the latest versions check if these errors 
(still) occur, please?

---
https://sirgazil.bitbucket.io/