Conda install of gcc ends with link error, error loading shared library libmpfr.so.4

LSB Version: core-9.20170808ubuntu1-noarch:security-9.20170808ubuntu1-noarch

Distributor ID: Ubuntu

Description: Ubuntu 18.04.3 LTS

Release: 18.04

Codename: bionic

Conda install of gcc results in the following:

    (base) userA@server:~$ conda install -c anaconda gcc

    Collecting package metadata (current_repodata.json): done
    Solving environment: done

    ## Package Plan ##

      environment location: /home/userA/anaconda3

      added / updated specs:
        - gcc


    The following NEW packages will be INSTALLED:

      cloog              anaconda/linux-64::cloog-0.18.0-0
      gcc                anaconda/linux-64::gcc-4.8.5-7
      isl                anaconda/linux-64::isl-0.12.2-0


    Proceed ([y]/n)? y

    Preparing transaction: done
    Verifying transaction: done
    Executing transaction: done
    ERROR conda.core.link:_execute(700): An error occurred while installing package 'anaconda::gcc-4.8.5-7'.
    Rolling back transaction: done

    LinkError: post-link script failed for package anaconda::gcc-4.8.5-7
    location of failed script: /home/userA/anaconda3/bin/.gcc-post-link.sh
    ==> script messages <==
    <None>
    ==> script output <==
    stdout: Installation failed: gcc is not able to compile a simple 'Hello, World' program.

    stderr: ln: failed to create symbolic link '/home/userA/anaconda3/lib/gcc/x86_64-unknown-linux-gnu/4.8.5/crt1.o': File exists
    ln: failed to create symbolic link '/home/userA/anaconda3/lib/gcc/x86_64-unknown-linux-gnu/4.8.5/crti.o': File exists
    ln: failed to create symbolic link '/home/userA/anaconda3/lib/gcc/x86_64-unknown-linux-gnu/4.8.5/crtn.o': File exists
    /home/userA/anaconda3/bin/../libexec/gcc/x86_64-unknown-linux-gnu/4.8.5/cc1: error while loading shared libraries: libmpfr.so.4: cannot open shared object file: No such file or directory

    return code: 1

    ()

Please advise. Happy to provide any additional helpful information.

***EDITED (most recent first):

OUTPUT of conda list | grep -E '(gmp|mpc|mpfr)

(base) userA@server:~$ conda list | grep -E '(gmp|mpc|mpfr)'
gmp                       6.1.2                hb3b607b_0    anaconda
gmpy2                     2.0.8            py37h10f8cd9_2
mpc                       1.1.0                h10f8cd9_1    anaconda
mpfr                      4.0.1                hdf1c602_3    anaconda