Building Virtualbox 7 on Slackware 15

I got this error while building with "kmk all"

warning: failed to load external entity "/usr/share/xml/docbook/schema/dtd/4.5/docbookx.dtd"
Could not parse DTD /usr/share/xml/docbook/schema/dtd/4.5/docbookx.dtd
kBuild: Validating /home/mustdos/Desktop/installbunch/VirtualBox-7.0.8/doc/manual/en_US/UserManual.xml
kmk: *** [/home/mustdos/Desktop/installbunch/VirtualBox-7.0.8/doc/manual/Makefile.kmk:553: /home/mustdos/Desktop/installbunch/VirtualBox-7.0.8/out/linux.amd64/release/obj/manual/en_US/validatemanual.run] Error 2
kmk: *** Waiting for unfinished jobs....
kBuild: Compiling vkathost - /home/mustdos/Desktop/installbunch/VirtualBox-7.0.8/src/VBox/Devices/Audio/DrvHostAudioOss.cpp
kBuild: Compiling vkathost - /home/mustdos/Desktop/installbunch/VirtualBox-7.0.8/src/VBox/Devices/Audio/DrvHostAudioPulseAudio.cpp
kBuild: Compiling vkathost - /home/mustdos/Desktop/installbunch/VirtualBox-7.0.8/src/VBox/Devices/Audio/DrvHostAudioAlsa.cpp
kmk: *** Exiting with status 2

However; I have the same file in a different directory

mustdos:/home/mustdos/Desktop/installbunch/docbook-xml> ls /usr/share/xm
1) xml/
2) xmlto/
3) xmms/
mustdos:/home/mustdos/Desktop/installbunch/docbook-xml> ls /usr/share/xml/docbook/
1) stylesheet/
2) xml-dtd-4.1.2/
3) xml-dtd-4.2/
4) xml-dtd-4.3/
5) xml-dtd-4.4/
6) xml-dtd-4.5/
7) xsl-stylesheets-1.79.2/
8) xsl-stylesheets/
mustdos:/home/mustdos/Desktop/installbunch/docbook-xml> ls /usr/share/xml/docbook/
1) stylesheet/
2) xml-dtd-4.1.2/
3) xml-dtd-4.2/
4) xml-dtd-4.3/
5) xml-dtd-4.4/
6) xml-dtd-4.5/
7) xsl-stylesheets-1.79.2/
8) xsl-stylesheets/
mustdos:/home/mustdos/Desktop/installbunch/docbook-xml> ls /usr/share/xml/docbook/
stylesheet xml-dtd-4.2 xml-dtd-4.4 xsl-stylesheets
xml-dtd-4.1.2 xml-dtd-4.3 xml-dtd-4.5 xsl-stylesheets-1.79.2
mustdos:/home/mustdos/Desktop/installbunch/docbook-xml> ls /usr/share/xml/docboomustdos:/home/mustdos/Desktop/installbunch/docbook-xml> ls /usr/share/xml/docbook/xml-dtd-4.5/
1) calstblx.dtd
2) dbcentx.mod
3) dbgenent.mod
4) dbhierx.mod
5) dbnotnx.mod
6) dbpoolx.mod
7) docbook.cat
8) docbookx.dtd
9) ent/
10) htmltblx.mod
11) soextblx.dtd
mustdos:/home/mustdos/Desktop/installbunch/docbook-xml> ls /usr/share/xml/docbook/xml-dtd-4.5/docbook.dtd