compiling postgresql with uuid-ossp failure

I have installed idempiere ERP which requires uuid-ossp library. I have
tried to recompile postgresql-11.2 with the option --with-uuid=ossp. When
run I

CREATE EXTENSION "uuid-ossp";

I get the following error:
ERROR: could not open extension control file
"/data/databases/postgres/pgsql11/share/extension/uuid-ossp.control": No
such file or directory.

select * from pg_available_extensions;

gives me this list (without uuid-ossp, of course):

name | default_version | installed_version |
comment
------------+-----------------+-------------------+-------------------------------------------
pltclu | 1.0 | | PL/TclU untrusted
procedural language
pltcl | 1.0 | | PL/Tcl procedural
language
plperl | 1.0 | | PL/Perl procedural
language
plperlu | 1.0 | | PL/PerlU untrusted
procedural language
plpythonu | 1.0 | | PL/PythonU untrusted
procedural language
plpython2u | 1.0 | | PL/Python2U untrusted
procedural language
plpgsql | 1.0 | 1.0 | PL/pgSQL procedural
language
(7 rows)

Is there a reason why this extension was not created during
compilation/installation?

Thanks