bug#50122: [core-updates-frozen] Gtk documentation generation fails.

[Mathieu Othacehe <othacehe@gnu.org>]

Hello,

The generation of the documentation of the Gnome projects is broken on
core-updates-frozen. Passing the "-Dgtk_doc=true" build option to evince
or libhandy packages results in the following error:

--8<---------------cut here---------------start------------->8---
Traceback (most recent call last):
  File "/gnu/store/6dk7w7g7kbr5cnp0kiym3f68l1g26xbx-python-3.9.6/lib/python3.9/shutil.py", line 806, in move
    os.rename(src, real_dst)
FileNotFoundError: [Errno 2] No such file or directory: '/home/mathieu/libhandy/_build/doc/html/libhandy.devhelp2' -> '/home/mathieu/libhandy/_build/doc/html/libhandy-1.devhelp2'

During handling of the above exception, another exception occurred:
--8<---------------cut here---------------end--------------->8---

According to strace, xsltproc is called to generate the
libhandy.devhelp2 document this way:

--8<---------------cut here---------------start------------->8---
/gnu/store/5fy04b79bmzajbgz21jibkgmn38frkrx-libxslt-1.1.34/bin/xsltproc --path /home/mathieu/libhandy/doc:/home/mathieu/libhandy/_build/doc --nonet --xinclude --stringparam gtkdoc.bookname libhandy --stringparam gtkdoc.version 1.33.1 /gnu/store/vh5gjvlbns7s26r8x6282165xqrk137l-gtk-doc-1.33.2/share/gtk-doc/data/gtk-doc.xsl ../handy-docs.xml
--8<---------------cut here---------------end--------------->8---

However the final document never shows up. The output log contains
several errors such as this one:

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Error: no ID for constraint linkend: "GtkDrawingArea".
--8<---------------cut here---------------end--------------->8---

that should be harmless.

Thanks,

Mathieu