* initial work to make use of an 'upstream' spack installation: this uses the DB of the upstream installation to check if a package is installed
* need to query upstream dbs when adding new record to local db
* prevent reindexing upstream DBs
* set prefix on specs read from DB based on path stored in install record
* check that Spack does not install packages that are recorded as installed in an upstream db
* externals do not add their path to install records - need to use 'external_path' to get path of upstream externals
* views need to check for upstream installations when linking metadata
* package and spec now calculate upstream installation properties on-demand themselves rather than depending on concretization to set these properties up-front. The added tests for upstream installations don't work with this new strategy so they need to be updated
* only refresh modules for local specs (not those in upstream packages); optionally generate local module files for packages installed upstream
* when a user tries to locate a module file for a package installed upstream, tell them to use the upstream spack instance to locate it
* support recursive upstream databases (allow upstream databases to use their own upstream databases)
* separate upstream config into separate file with its own schema; each entry now also includes a name
* metadata_dir is no longer customizable on a per-instance basis for YamlDirectoryLayout
* treat metadata_dir as an instance variable but dont set it from kwargs; this follows several other hardcoded variables which must be consistent between upstream and downstream DBs. Also update DirectoryLayout.metadata_path to work entirely with Spec.prefix, since Spec.prefix is set from the DB when available (so metadata_path was duplicating that logic)
- `spack env activate foo`: sets SPACK_ENV to the current active env name
- `spack env deactivate`: unsets SPACK_ENV, deactivates the environment
- added support to setup_env.sh and setup_env.csh
- other env commands work properly with SPACK_ENV, as with an environment
arguments.
- command-line --env arguments take precedence over the active
environment, if given.
- remove the old LGPL license headers from all files in Spack
- add SPDX headers to all files
- core and most packages are (Apache-2.0 OR MIT)
- a very small number of remaining packages are LGPL-2.1-only
- The setup-env.sh script currently makes two calls to spack, but it
should only need to make one.
- Add a fast-path shell setup routine in `main.py` to allow the shell
setup to happen in a single, fast call that doesn't load more than it
needs to.
- This simplifies setup code, as it has to eval what Spack prints
- TODO: consider eventually making the whole setup script the output of a
spack command
- replace `spack.config.get_configuration()` with `spack.config.config()`
- replace `get_config`/`update_config` with `get`, `set`
- add a path syntax that can be used to refer to specific config options
without firt getting the entire configuration dict
- update usages of `get_config` and `update_config` to use `get` and `set`
* Edits to get setup-env.csh working better.
Autosets the sys_type a la setup-env.sh
* More stealing from bash setup script for module roots
* Add error message if SPACK_ROOT isn't set
* Remove _sp_lmod_root per Adam J Stewart
