Spack did not support usage of the `--config-scope` option in
combination with an environment: In `lib/spack/spack/main.py`,
`spack.config.command_line_scopes` is set equal to any config scopes
passed by the `--config-scope` option. However, this is done after
activating an environment. In the process of activating an environment,
the `spack.config.config` singleton is instantiated, so later setting of
`spack.config.command_line_scopes` is ignored.
This commit sets command line scopes before activating an environment to
ensure that they are included in the configuration.
Co-authored-by: Tim Fuller <tjfulle@sandia.gov>
bd236918dd