Error building docs

Hi,
 
I'm getting this error building docs (from commit
e4c27f5befbfc80a1bf96fc93256dce08b148238):
 
$ make docs  
make -C doc all
make[1]: Entering directory '/home/andreak/dev/postgresql/doc'
make -C src all
make[2]: Entering directory '/home/andreak/dev/postgresql/doc/src'
make -C sgml all
make[3]: Entering directory '/home/andreak/dev/postgresql/doc/src/sgml'
{ \
 echo "<!ENTITY version \"10devel\">"; \
 echo "<!ENTITY majorversion \"10\">"; \
} > version.sgml
'/usr/bin/perl' ./mk_feature_tables.pl YES
../../../src/backend/catalog/sql_feature_packages.txt
../../../src/backend/catalog/sql_features.txt > features-supported.sgml
'/usr/bin/perl' ./mk_feature_tables.pl NO
../../../src/backend/catalog/sql_feature_packages.txt
../../../src/backend/catalog/sql_features.txt > features-unsupported.sgml
'/usr/bin/perl' ./generate-errcodes-table.pl
../../../src/backend/utils/errcodes.txt > errcodes-table.sgml
osx -D. -x lower -i include-xslt-index postgres.sgml >postgres.xmltmp
osx:postgres.sgml:3:55:W: cannot generate system identifier for public text
"-//OASIS//DTD DocBook V4.2//EN"
osx:postgres.sgml:12:0:E: reference to entity "BOOK" for which no system
identifier could be generated
osx:postgres.sgml:3:0: entity was defined here
osx:postgres.sgml:12:0:E: DTD did not contain element declaration for
document type name
osx:postgres.sgml:14:9:E: there is no attribute "ID"
osx:postgres.sgml:14:19:E: element "BOOK" undefined
osx:postgres.sgml:15:7:E: element "TITLE" undefined
osx:postgres.sgml:17:10:E: element "BOOKINFO" undefined
osx:postgres.sgml:18:13:E: element "CORPAUTHOR" undefined
osx:postgres.sgml:19:14:E: element "PRODUCTNAME" undefined
osx:postgres.sgml:20:16:E: element "PRODUCTNUMBER" undefined

 
$ osx --version
osx:I: "OpenSP" version "1.5.2"

Any hints?
 
Thanks.
 
-- Andreas Joseph Krogh
CTO / Partner - Visena AS
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