Here is the topmost build error:

Making all in spec
make[3]: Entering directory `/var/tmp/portage/hal-0.5.7-r1/work/hal-0.5.7/doc/sp ec'
/usr/bin/docbook2html --nochunks hal-spec.xml -o .
Using catalogs: /usr/share/sgml/docbook/xml-simple-dtd-1.0/catalog, /usr/share/s gml/docbook/sgml-dtd-3.0/catalog, /usr/share/sgml/docbook/sgml-dtd-3.1/catalog, /usr/share/sgml/docbook/sgml-dtd-4.0/catalog, /usr/share/sgml/docbook/sgml-dtd-4 .1/catalog, /usr/share/sgml/docbook/sgml-dtd-4.2/catalog, /usr/share/sgml/docboo k/sgml-dtd-4.4/catalog, /usr/share/sgml/docbook/dsssl-stylesheets-1.79/catalog, /usr/share/sgml/xml-iso-entities-8879.1986/catalog, /usr/share/sgml/sgml-iso-ent ities-8879.1986/catalog, /usr/share/sgml/openjade-1.3.2/dsssl/catalog, /usr/shar e/sgml/openjade-1.3.2/catalog, /usr/share/sgml/opensp-1.5/OpenSP/catalog
Using stylesheet: /usr/share/sgml/docbook/utils-0.6.14/docbook-utils.dsl#html
Working on: /var/tmp/portage/hal-0.5.7-r1/work/hal-0.5.7/doc/spec/hal-spec.xml
jade:/var/tmp/portage/hal-0.5.7-r1/work/hal-0.5.7/doc/spec/hal-spec.xml:3:119:E:  URL not supported by this version
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/../common/dbtable.dsl:2 24:13:E: 2nd argument for primitive "ancestor" of wrong type: "#<unknown object 136983568>" not a singleton node list
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/../common/dbtable.dsl:2 24:13:E: 2nd argument for primitive "ancestor" of wrong type: "#<unknown object 136983568>" not a singleton node list
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/dblink.dsl:203:1:E: XRe f LinkEnd to missing ID 'dbus-api'
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/dblink.dsl:203:1:E: XRe f LinkEnd to missing ID 'enforcing-policy'
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/dblink.dsl:203:1:E: XRe f LinkEnd to missing ID 'enforcing-policy'
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/dblink.dsl:203:1:E: XRe f LinkEnd to missing ID 'device-capabilities'
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/dblink.dsl:203:1:E: XRe f LinkEnd to missing ID 'device-properties'
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/dblink.dsl:203:1:E: XRe f LinkEnd to missing ID 'device-properties'
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/../common/dbtable.dsl:2 24:13:E: 2nd argument for primitive "ancestor" of wrong type: "#<unknown object 136983568>" not a singleton node list
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/../common/dbtable.dsl:2 24:13:E: 2nd argument for primitive "ancestor" of wrong type: "#<unknown object 136983568>" not a singleton node list
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/../common/dbtable.dsl:2 24:13:E: 2nd argument for primitive "ancestor" of wrong type: "#<unknown object 

(repeats many times)

jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/../common/dbtable.dsl:2 24:13:E: 2nd argument for primitive "ancestor" of wrong type: "#<unknown object 136983568>" not a singleton node list
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/dblink.dsl:203:1:E: XRe f LinkEnd to missing ID 'device-properties-storage'
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/dblink.dsl:203:1:E: XRe f LinkEnd to missing ID 'properties-policy'
jade:E: cannot find "../../fdi/policy/10osvendor/10-storage-policy.fdi"; tried " ../../fdi/policy/10osvendor/10-storage-policy.fdi", "/usr/share/sgml/../../fdi/p olicy/10osvendor/10-storage-policy.fdi"
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/../common/dbtable.dsl:2 24:13:E: 2nd argument for primitive "ancestor" of wrong type: "#<unknown object 136983568>" not a singleton node list
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/../common/dbtable.dsl:2 24:13:E: 2nd argument for primitive "ancestor" of wrong type: "#<unknown object 136983568>" not a singleton node list
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/dblink.dsl:203:1:E: XRe f LinkEnd to missing ID 'using-devices'
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/dblink.dsl:203:1:E: XRe f LinkEnd to missing ID 'properties-policy'
jade:/usr/share/sgml/docbook/dsssl-stylesheets-1.79/html/dblink.dsl:203:1:E: XRe f LinkEnd to missing ID 'stor-vol-policy'
make[3]: *** [hal-spec.html] Error 8
make[3]: Leaving directory `/var/tmp/portage/hal-0.5.7-r1/work/hal-0.5.7/doc/spe c'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/var/tmp/portage/hal-0.5.7-r1/work/hal-0.5.7/doc'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/var/tmp/portage/hal-0.5.7-r1/work/hal-0.5.7'
make: *** [all] Error 2

!!! ERROR: sys-apps/hal-0.5.7-r1 failed.
Call stack:
  ebuild.sh, line 1539:   Called dyn_compile
  ebuild.sh, line 939:   Called src_compile
  hal-0.5.7-r1.ebuild, line 133:   Called die

!!! make failed
!!! If you need support, post the topmost build error, and the call stack if rel evant.