Possible bug ¿? missing "ucol.h" in postgre installation

Hi guys !

Please forgive me if I do not do it correctly, it is the first time that
I write to this list and not know if I do it properly.

We have a problem with a PostgreSQL 16 installation, I am preparing this
server to be the destination for the migration of another database in
PostgreSQL 15, the details of the versions are:

15.8    ->    16.7

As an example, we take the attempt to install the "orafce" extension in
the new system, although it is not the only one in which this happens.
When installing, we get the following error:

/usr/pgsql-16/include/server/utils/pg_locale.h:19:10: fatal error:
unicode/ucol.h: No such file or directory
   19 | #include <unicode/ucol.h>
      |          ^~~~~~~~~~~~~~~~

When reviewing the file:
"//usr/pgsql-16/include/server/utils/pg_locale.h/" We see the references
to the missing file "ucol.h". We are looking for this last file:

* In our system
* In AlmaLinux repositories
* In Red Hat repositories
* In RPM find
* With the help of rpm and yum command

We didn't find any reference to it anywhere except on github: (
https://github.com/unicode-org/icu/blob/main/icu4c/source/i18n/unicode/ucol.h
).

The fact is that we reviewed the other server that we have in version
15.8 and this file does not exist either, but nevertheless we have not
had problems installing the following extensions:

postgres=# \dx
Listado de extensiones instaladas
       Nombre       | Versión |  Esquema
|                                          Descripción
--------------------+---------+------------+-----------------------------------------------------------------------------------------------
 dblink             | 1.2     | public | connect to other
PostgreSQL databases from within a database
 orafce             | 4.12    | public | Functions and operators
that emulate a subset of functions and packages from the Oracle RDBMS
 pg_buffercache     | 1.3     | public | examine the shared buffer
cache
 pg_cron            | 1.6     | pg_catalog | Job scheduler for
PostgreSQL
 pg_hint_plan       | 1.5.2   | hint_plan |
 pg_partman         | 5.1.0   | public | Extension to manage
partitioned tables by time or ID
 pg_prewarm         | 1.2     | public | prewarm relation data
 pg_stat_statements | 1.10    | public | track planning and
execution statistics of all SQL statements executed
 plpgsql            | 1.0     | pg_catalog | PL/pgSQL procedural
language
 vector             | 0.7.4   | public | vector data type and
ivfflat and hnsw access methods
(10 filas)

Attached:

* A system file with PostgreSQL 15 and another file with the
PostgreSQL 16 system with the following data:
o Version revision
o List of installed extensions
o Search with the "root" user for the "ucol.h" file
o Complete OS release
* List of "*.h" files that are distributed with the installation of
postgreSQL in "//usr/pgsql-15/include/server/utils/" and
"//usr/pgsql-16/include/server/utils/" respectively
* We also attach a file for each system, one from the PostgreSQL
server 15 and another from 16 with the list of all the RPM packages
installed in the OS.

I also found information that requests the packages
"/icu-67.1-9.el9.x86_64/" and "/libicu-67.1-9.el9.x86_64/" to be
installed, but these do not solve the problem on my system. I even tried
to edit the "/pg_locale.h" /file to remove these references, but I’m not
familiar with the source code and logically make a lot of mistakes.

I think this is an error, or maybe a bug, since there are changes in the
"/pg_locale.h/" file of both versions (I attach the output of the diff
command), and one thing that has surprised me a lot, is that the package
"dev" of the postgreSQL version was not well in the repository of my
linux distribution ( Rocky / Alma / RH ) , and I had to download it
directly from the web of the postgreSQL project, Could there be bugs or
errors? , would it be possible to take the file "/pg_locale. h/" from an
earlier version?

Thank you very much in advance!

Regards ,

Jose Mojada