bug#35422: LibreOffice builds for me, but not on CI server

[Ben Sturmfels]

Hi Folks,

When I `guix pull` and `guix package --manifest` the system will usually
need build LibreOffice. The build succeeds, but it takes several hours.
It would be great to resolve whatever is preventing it building on the
CI server.

Hydra currently shows that the LibreOffice cannot be build due to failed
dependencies:

 - libcmis
 - libepubgen

For example: http://hydra.gnu.org/build/3443570

Both these packages build successfully for me, but on Hydra they fail at the
testing phase, with exceptions mentioning "entropy_error" and
"getrandom".

The Boost docs say:

  The exception boost::uuids::entropy_error is thrown if there is an
  error getting entropy from the operating system.

  https://www.boost.org/doc/libs/1_69_0/libs/uuid/doc/uuid.html

I can see though that providing entropy does work against the goal of
reproducible builds though. Is this a case where the tests should be
modified or disabled?

Regards,
Ben