Given following log snippets, their explanation, and nothing else, explain what failure, if any, occurred during build of this package.

  Snippets are in a format of [X] : [Y], where [X] is a log snippet, and [Y] is the explanation.

  Snippets are delimited with '================'.

  Drawing on information from all snippets, provide a concise explanation of the issue and recommend a solution.

  Explanation of the issue, and recommended solution, should take a handful of sentences.

  Snippets:

  [CC=clang]: [clang is being used as the C compiler.]
=============
[CXX=clang++]: [clang++ is being used as the C++ compiler.]
=============
[checking whether the Fortran compiler works... no
configure: error: in '/builddir/build/BUILD/arpack-3.9.1-build/arpack-3.9.1/src':
configure: error: Fortran compiler cannot create executables
See 'config.log' for more details]: [This is the error message produced by the configuration script which has failed.]

Issue: The configure script failed because it is trying to use clang C/C++ flags with the gfortran compiler.  gfortran does not support all clang flags so the fortran detection fails.
Resolution: This needs to be fixed in Fedora redhat-rpm-config: https://src.fedoraproject.org/rpms/redhat-rpm-config/pull-request/250

You can work around this be manually specifying the FORTRAN flangs and ensure they are compatible with gfortran.