Description of problem:

When updating the ibus-libs package the postun scriptlet fails and emits an error:

Non-fatal POSTUN scriptlet failur in rpm package ibus-libs

Version-Release number of selected component (if applicable):

ibus-libs-1.5.17-5.fc27.x86_64 (and others)

How reproducible:

Always.

Steps to Reproduce:
1. Update ibus-libs (using a method that doesn's silently hide errors)
2. See the error message

Actual results:

You can see that there is an issue using the command
$ echo ---- ; rpm -q --scripts ibus-libs; echo ----
----
postinstall program: /sbin/ldconfig
postuninstall scriptlet (using /sbin/ldconfig):

# FIXME: no version number
----

Expected results:

What you expect is the following:
$ echo ---- ; rpm -q --scripts -p results_ibus/1.5.17/7.fc28/ibus-libs-1.5.17-7.fc27.x86_64.rpm ; echo ----
----
postinstall program: /sbin/ldconfig
postuninstall program: /sbin/ldconfig
----

I.e. The %postun script should be empty, like the %post script is. The FIXME comment in the specfile is currently placed in the %postun scriptlet, and /sbin/ldconfig does not understand it and throws an error.

Additional info:

This can be fixed by moving the FIXME comment into the %files section:

diff --git a/ibus.spec b/ibus.spec
index b0ac4ca..8ff21f7 100644
--- a/ibus.spec
+++ b/ibus.spec
@@ -346,8 +346,8 @@ dconf update || :
 
 %ldconfig_scriptlets libs
 
-# FIXME: no version number
 %files -f %{name}10.lang
+# FIXME: no version number
 %doc AUTHORS COPYING README
 %dir %{_datadir}/ibus/
 %{_bindir}/ibus

The rpm used in the "Expected results" section was built with this change.