new concretizer: changes compilers to avoid compiler conflict in package #20019
Description
Steps to reproduce the issue
With GCC7 and Clang 6 installed, you get:
$ spack spec netlib-scalapack %gcc@:7 ^openblas
^[email protected]%[email protected] ... arch=linux-ubuntu18.04-x86_64
^[email protected]%[email protected] ... arch=linux-ubuntu18.04-x86_64where it mixes GCC and Clang to work around
conflicts('%gcc@:8.2.99', when='@0.3.11:')
defined in openblas.
Instead it should just take [email protected] and compile with GCC.