[Ifeffit] Demeter installation on Debian

[Bruce Ravel]

Just to follow up on this thread, after a lengthy and detailed-filled
off-line conversation with Isabelle, we managed to clear up several
issues related to Demeter's build scripts.  Isabelle was very patient
and helpful.  Several improvements have been checked into the github
repository.

Isabelle's initial question was about a failed installation somewhere
deep in Demeter's tree of dependencies when installing on a Debian
linux computer.  In its build script, Demeter identifies a list of
packages that it uses.  Each of those packages has its own list of
dependencies.  One of Demeter's installation steps attempts to
retrieve the entire tree of dependencies from the repository of Perl
packages and build each one.

In Isabelle's case, a couple of items deep in the dependency tree
failed to install correctly.

Demeter does not much care how these dependencies get resolved.  In
the case of Isabelle's Debian linux computer, she was able to use the
Debian packaging system to meet the dependencies that, for some
reason, did not install correctly using Demeter's build script.

For example, one of the problems she ran into gave an error message
that read, in part:

    Can't locate PerlIO/utf8_strict.pm in @INC

It turns out that this package:

    https://metacpan.org/pod/PerlIO::utf8_strict

was deep in the dependency tree.  (Something called Config::INI is an
immediate dependency of Demeter, PerlIO::utf8_strict is one of its
dependencies.)  In Debian, this package is called
"libperlio-utf8-strict-perl".  By installing the Debian package, she
met Demeter's requirement.  Many of the packages that Demeter's build
script attempts to download and build could be installed in this way.

The reason I am explaining all this is because this is a common sort
of problem for those installing Demeter from source code.  I wanted to
leave this explanation in the m ailing list archives for the benefit
of anyone in the future who runs into a similar snag.

Cheers,
B

-- 
  Bruce Ravel  ------------------------------------ bravel at bnl.gov

  National Institute of Standards and Technology
  Synchrotron Science Group at NSLS-II
  Building 535A
  Upton NY, 11973

  Homepage:    http://bruceravel.github.io/home/
  Software:    https://github.com/bruceravel
  Demeter:     http://bruceravel.github.io/demeter/