[postgre@rac01 contrib]$ cd xml2/
[postgre@rac01 xml2]$ ll
total 108
drwxrwxrwx 2 postgre postgre 4096 May 23 05:18 expected
-rw-r--r-- 1 postgre postgre 497 May 23 05:08 Makefile
-rw-r--r-- 1 postgre postgre 810 May 23 05:08 meson.build
-rwxrwxr-x 1 postgre postgre 24824 Jul 28 18:00 pgxml.so
drwxrwxrwx 2 postgre postgre 4096 May 23 05:18 sql
-rw-r--r-- 1 postgre postgre 944 May 23 05:08 xml2--1.0--1.1.sql
-rw-r--r-- 1 postgre postgre 2049 May 23 05:08 xml2--1.1.sql
-rw-r--r-- 1 postgre postgre 182 May 23 05:08 xml2.control
-rw-r--r-- 1 postgre postgre 17393 May 23 05:08 xpath.c
-rw-rw-r-- 1 postgre postgre 16760 Jul 28 18:00 xpath.o
-rw-r--r-- 1 postgre postgre 6063 May 23 05:08 xslt_proc.c
-rw-rw-r-- 1 postgre postgre 2328 Jul 28 18:00 xslt_proc.o
[postgre@rac01 xml2]$
[postgre@rac01 xml2]$
[postgre@rac01 xml2]$
[postgre@rac01 xml2]$
[postgre@rac01 xml2]$ make
make -C ../../src/backend generated-headers
make[1]: Entering directory `/u01/postgresql-16beta1/src/backend'
make -C catalog distprep generated-header-symlinks
make[2]: Entering directory `/u01/postgresql-16beta1/src/backend/catalog'
make[2]: Nothing to be done for `distprep'.
make[2]: Nothing to be done for `generated-header-symlinks'.
make[2]: Leaving directory `/u01/postgresql-16beta1/src/backend/catalog'
make -C nodes distprep generated-header-symlinks
make[2]: Entering directory `/u01/postgresql-16beta1/src/backend/nodes'
make[2]: Nothing to be done for `distprep'.
make[2]: Nothing to be done for `generated-header-symlinks'.
make[2]: Leaving directory `/u01/postgresql-16beta1/src/backend/nodes'
make -C utils distprep generated-header-symlinks
make[2]: Entering directory `/u01/postgresql-16beta1/src/backend/utils'
make[2]: Nothing to be done for `distprep'.
make[2]: Nothing to be done for `generated-header-symlinks'.
make[2]: Leaving directory `/u01/postgresql-16beta1/src/backend/utils'
make[1]: Leaving directory `/u01/postgresql-16beta1/src/backend'
[postgre@rac01 xml2]$ echo $?
0
[postgre@rac01 xml2]$ make install
make -C ../../src/backend generated-headers
make[1]: Entering directory `/u01/postgresql-16beta1/src/backend'
make -C catalog distprep generated-header-symlinks
make[2]: Entering directory `/u01/postgresql-16beta1/src/backend/catalog'
make[2]: Nothing to be done for `distprep'.
make[2]: Nothing to be done for `generated-header-symlinks'.
make[2]: Leaving directory `/u01/postgresql-16beta1/src/backend/catalog'
make -C nodes distprep generated-header-symlinks
make[2]: Entering directory `/u01/postgresql-16beta1/src/backend/nodes'
make[2]: Nothing to be done for `distprep'.
make[2]: Nothing to be done for `generated-header-symlinks'.
make[2]: Leaving directory `/u01/postgresql-16beta1/src/backend/nodes'
make -C utils distprep generated-header-symlinks
make[2]: Entering directory `/u01/postgresql-16beta1/src/backend/utils'
make[2]: Nothing to be done for `distprep'.
make[2]: Nothing to be done for `generated-header-symlinks'.
make[2]: Leaving directory `/u01/postgresql-16beta1/src/backend/utils'
make[1]: Leaving directory `/u01/postgresql-16beta1/src/backend'
/bin/mkdir -p '/u01/postgresql/dbhome/16.1/lib'
/bin/mkdir -p '/u01/postgresql/dbhome/16.1/share/extension'
/bin/mkdir -p '/u01/postgresql/dbhome/16.1/share/extension'
/bin/install -c -m 755 pgxml.so '/u01/postgresql/dbhome/16.1/lib/pgxml.so'
/bin/install -c -m 644 ./xml2.control '/u01/postgresql/dbhome/16.1/share/extension/'
/bin/install -c -m 644 ./xml2--1.1.sql ./xml2--1.0--1.1.sql '/u01/postgresql/dbhome/16.1/share/extension/'
[postgre@rac01 xml2]$ echo $?
0
[postgre@rac01 xml2]$ psql
psql (16beta1)
Type "help" for help.

postgres=# create extension xml2;
ERROR: could not load library "/u01/postgresql/dbhome/16.1/lib/pgxml.so": /u01/postgresql/dbhome/16.1/lib/pgxml.so: undefined symbol: xml_ereport
postgres=#