Steps to reproduce the issue
With GCC7 and Clang 6 installed, you get:
$ spack spec netlib-scalapack %gcc@:7 ^openblas
^netlib-scalapack@2.1.0%gcc@7.5.0 ... arch=linux-ubuntu18.04-x86_64
^openblas@0.3.12%clang@6.0.0 ... arch=linux-ubuntu18.04-x86_64
where 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 openblas@0.3.10 and compile with GCC.
Steps to reproduce the issue
With GCC7 and Clang 6 installed, you get:
where it mixes GCC and Clang to work around
defined in openblas.
Instead it should just take openblas@0.3.10 and compile with GCC.