Should be "/xml/xsl/docbook-xsl-1.79.2/" instead of "/xml/xsl/docbook-xsl-1.79.1/", otherwise fails with:

FAILED: docs/gdk-pixbuf-csource.1 

/gnu/store/8mcjhrc6yir9gzrp0y71nj254giw75bd-libxslt-1.1.34/bin/xsltproc --nonet --stringparam man.output.quietly 1 --stringparam funcsynopsis.style ansi --stringparam man.th.extra1.suppress 1 --stringparam man.authors.section.enabled 0 --stringparam man.copyright.section.enabled 0 -o docs/gdk-pixbuf-csource.1 /gnu/store/6jxdry6q9yj4rw7ska0aniqjf42b6ply-docbook-xsl-1.79.2/xml/xsl/docbook-xsl-1.79.1/manpages/docbook.xsl ../gdk-pixbuf-2.40.0/docs/gdk-pixbuf-csource.xml
warning: failed to load external entity "/gnu/store/6jxdry6q9yj4rw7ska0aniqjf42b6ply-docbook-xsl-1.79.2/xml/xsl/docbook-xsl-1.79.1/manpages/docbook.xsl"
cannot parse /gnu/store/6jxdry6q9yj4rw7ska0aniqjf42b6ply-docbook-xsl-1.79.2/xml/xsl/docbook-xsl-1.79.1/manpages/docbook.xsl
[4/152] Compiling C object 'gdk-pixbuf/pixops/a255f19@@timescale@exe/timescale.c.o'.
[5/152] Generating gdk-pixbuf-enum-types.h with a meson_exe.py custom command.
[6/152] Compiling C object 'gdk-pixbuf/pixops/a255f19@@pixops@sta/pixops.c.o'.
ninja: build stopped: subcommand failed.
command "ninja" "-j" "4" failed with status 1
builder for `/gnu/store/8j55f3i81w274iif5pnsbyxp170s9814-gdk-pixbuf-2.40.0.drv' failed with exit code 1
build of /gnu/store/8j55f3i81w274iif5pnsbyxp170s9814-gdk-pixbuf-2.40.0.drv failed
View build log at '/var/log/guix/drvs/8j/55f3i81w274iif5pnsbyxp170s9814-gdk-pixbuf-2.40.0.drv.bz2'.
guix build: error: build of `/gnu/store/8j55f3i81w274iif5pnsbyxp170s9814-gdk-pixbuf-2.40.0.drv' failed