Postfix/sendmail warning: ICU library initialization failed: U_FILE_ACCESS_ERROR

In our selfhosted GitLab instance (V14.8) each e-mail sent from GitLab triggers a warning related to the ICU library. We have not been able to figure out what causes the warning. E-mails are sent and received, so it does not seem to have an effect, but we would prefer to find out what triffers the warning.

Excerpt from journalctl:

journalctl --unit=gitlab-runsvdir --since=yesterday
-- Logs begin at Fri 2022-02-18 03:15:16 CET, end at Thu 2022-02-24 11:01:08 CET. --
Feb 23 01:50:20 <hostname_removed> postfix/sendmail[26913]: warning: ICU library initialization failed: U_FILE_ACCESS_ERROR
Feb 23 09:02:36 <hostname_removed> postfix/sendmail[37618]: warning: ICU library initialization failed: U_FILE_ACCESS_ERROR
Feb 23 09:02:36 <hostname_removed> postfix/sendmail[37620]: warning: ICU library initialization failed: U_FILE_ACCESS_ERROR
Feb 23 09:05:12 <hostname_removed> postfix/sendmail[38241]: warning: ICU library initialization failed: U_FILE_ACCESS_ERROR

Some more details about our host system:

  • SUSE Linux Enterprise 15
  • postfix 3.5.9

System-wide we use libicu65, gitlab comes with libicu57 it seems. Could this be a problem?

find / -name "libicu*" -type f
/opt/gitlab/embedded/lib/libicutu.so.57.1
/opt/gitlab/embedded/lib/libicutest.so.57.1
/opt/gitlab/embedded/lib/libiculx.so.57.1
/opt/gitlab/embedded/lib/libicuio.so.57.1
/opt/gitlab/embedded/lib/libicudata.so.57.1
/opt/gitlab/embedded/lib/libicuuc.so.57.1
/opt/gitlab/embedded/lib/libicui18n.so.57.1
/opt/gitlab/embedded/lib/libicule.so.57.1
/opt/gitlab/LICENSES/libicu-LICENSE
/usr/lib64/libicui18n.so.suse65.1
/usr/lib64/libicuio.so.suse65.1
/usr/lib64/libicudata.so.suse65.1
/usr/lib64/libicuuc.so.suse65.1
/usr/lib64/libicutest.so.suse65.1
/usr/lib64/libicutu.so.suse65.1

Some thoughts:

  • Cold it be that our postfix configuration is incorrect? I did not want to post the entire postconf, let me know which settings we should check.
  • Could it be related to a chroot issue? There was on up until postfix 3.5.2 (Postfix stable release 3.5.2 and legacy releases 3.4.12, 3.3.10, 3.2.15).
  • We also checked whether it might be related to the hostname. The hostname of the server is actually different from the hostname of the GitLab instance. The hostname of the GitLab instance is an alias for the actual hostname. We changed this, but it did not seem to be causing the problems.

Any ideas? Thanks a lot!