Note: There is no shell prompt offered at end of that error message.

Today, the same final error message was received, but a shell prompt was obtained for some reason:

thisuser@thishost ~ $ u
Repositories synchronization
 * Checking current binhost ...                                                             [ ok ]
 * Checking Distros updates ...                                                             [ ok ]
 * Checking Calculate updates ...                                                           [ ok ]
 * Checking Gentoo updates ...                                                              [ ok ]
 * Synchronization finished
System configuration
 * Update server http://miroir.linuxtricks.fr/calculate
Updating packages
 * Calculating dependencies ...
 * Listing packages for installation  
 * An library to provide useful functions commonly found on BSD systems (U) dev-libs/libbsd-0.9.1 (228 KiB)
 * Simple and small C++ XML parser (U) dev-libs/tinyxml-2.6.2-r3 (94 KiB)
 * A set of Calculate utilities for system installation, build and upgrade (U) sys-apps/calculate-utils-3.6.0.11 (2707 KiB)
 * 3 packages will be installed, 3028 KiB will be downloaded

Would you like to merge these packages? (Yes/No): y
 * (1 of 3) An library to provide useful functions commonly found on BSD systems
 * Emerging dev-libs/libbsd-0.9.1 ...                                                       [ ok ]
 * (2 of 3) Simple and small C++ XML parser
 * Emerging dev-libs/tinyxml-2.6.2-r3 ...                                                   [ ok ]
 * Installing dev-libs/tinyxml-2.6.2-r3 [2.6.2-r2] ...                                      [ ok ]
 * Installing dev-libs/libbsd-0.9.1 [0.8.6] ...                                             [ ok ]
 * (3 of 3) A set of Calculate utilities for system installation, build and upgrade
 * Emerging sys-apps/calculate-utils-3.6.0.11 ...                                           [ ok ]
 * Installing sys-apps/calculate-utils-3.6.0.11 [3.6.0.8] ...                               [ ok ]
Cleaning the system from needless packages
 * Calculating dependencies ...                                                             [ ok ]
Rebuilding dependent modules
 * Updating preserved libraries |Traceback (most recent call last):
  File "/usr/lib64/python2.7/site-packages/calculate/console/application/function.py", line 186, in analysis
    self.get_messages()
  File "/usr/lib64/python2.7/site-packages/calculate/console/application/function.py", line 214, in get_messages
    current_frame = self.get_client_frame()
  File "/usr/lib64/python2.7/site-packages/calculate/console/application/function.py", line 203, in get_client_frame
    "console")
  File "/usr/lib64/python2.7/site-packages/sudsds/client.py", line 535, in __call__
    return client.invoke(args, kwargs)
  File "/usr/lib64/python2.7/site-packages/sudsds/client.py", line 595, in invoke
    result = self.send(msg)
  File "/usr/lib64/python2.7/site-packages/sudsds/client.py", line 630, in send
    result = self.failed(binding, e)
  File "/usr/lib64/python2.7/site-packages/sudsds/client.py", line 681, in failed
    r, p = binding.get_fault(reply)
  File "/usr/lib64/python2.7/site-packages/sudsds/bindings/binding.py", line 235, in get_fault
    raise WebFault(p, faultroot)
WebFault: Server raised fault: ''utf8' codec can't decode byte 0x80 in position 967: invalid start byte'                                                                                           /Error:  <urlopen error [Errno 104] Connection reset by peer>
thisuser@thishost ~ $

There may have been one or more update(s) where somehow I didn't notice or didn't get prompted to update configuration files. The error messages stopped after trying the following to prompt which configuration files needed updating:

sudo dispatch-conf

Four configuration files needed updating by answering 'u' when prompted.

Therefore, this 'bug' may not be one after all, and this post may be marked as 'closed' (or 'resolved'?).