* Deactivate previous env before activating new one
Currently on develop you can run `spack env activate` multiple times to switch
between environments, but they leave traces, even though Spack only supports
one active environment at a time.
Currently:
```console
$ spack env create a
$ spack env create b
$ spack env activate -p a
[a] $ spack env activate -p b
[b] [a] $ spack env activate -p b
[a] [b] [a] $ spack env activate -p a
[a] [b] [c] $ echo $MANPATH | tr ":" "\n"
/path/to/environments/a/.spack-env/view/share/man
/path/to/environments/a/.spack-env/view/man
/path/to/environments/b/.spack-env/view/share/man
/path/to/environments/b/.spack-env/view/man
```
This PR fixes that:
```console
$ spack env activate -p a
[a] $ spack env activate -p b
[b] $ spack env activate -p a
[a] $ echo $MANPATH | tr ":" "\n"
/path/to/environments/a/.spack-env/view/share/man
/path/to/environments/a/.spack-env/view/man
```
Creates an environment in a temporary directory and activates it, which
is useful for a quick ephemeral environment:
```
$ spack env activate -p --temp
[spack-1a203lyg] $ spack add zlib
==> Adding zlib to environment /tmp/spack-1a203lyg
==> Updating view at /tmp/spack-1a203lyg/.spack-env/view
```
- [x] add `concretize.lp`, `spack.yaml`, etc. to licensed files
- [x] update all licensed files to say 2013-2021 using
`spack license update-copyright-year`
- [x] appease mypy with some additions to package.py that needed
for oneapi.py
* share/spack/setup-env.fish file to setup environment in fish shell
* setup-env.fish testing script
* Update share/spack/setup-env.fish
Co-Authored-By: Elsa Gonsiorowski, PhD <gonsie@me.com>
* Update share/spack/qa/setup-env-test.fish
Co-Authored-By: Adam J. Stewart <ajstewart426@gmail.com>
* updates completions using `spack commands --update-completion`
* added stderr-nocaret warning
* added fish shell tests to CI system
Co-authored-by: becker33 <becker33@llnl.gov>
Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>
Co-authored-by: Elsa Gonsiorowski, PhD <gonsie@me.com>
