Environments are nowm by default, created with views. When activated, if an environment includes a view, this view will be added to `PATH`, `CPATH`, and other shell variables to expose the Spack environment in the user's shell.
Example:
```
spack env create e1 #by default this will maintain a view in the directory Spack maintains for the env
spack env create e1 --with-view=/abs/path/to/anywhere
spack env create e1 --without-view
```
The `spack.yaml` manifest file now looks like this:
```
spack:
specs:
- python
view: true #or false, or a string
```
These commands can be used to control the view configuration for the active environment, without hand-editing the `spack.yaml` file:
```
spack env view enable
spack env view envable /abs/path/to/anywhere
spack env view disable
```
Views are automatically updated when specs are installed to an environment. A view only maintains one copy of any package. An environment may refer to a package multiple times, in particular if it appears as a dependency. This PR establishes a prioritization for which environment specs are added to views: a spec has higher priority if it was concretized first. This does not necessarily exactly match the order in which specs were added, for example, given `X->Z` and `Y->Z'`:
```
spack env activate e1
spack add X
spack install Y # immediately concretizes and installs Y and Z'
spack install # concretizes X and Z
```
In this case `Z'` will be favored over `Z`.
Specs in the environment must be concrete and installed to be added to the view, so there is another minor ordering effect: by default the view maintained for the environment ignores file conflicts between packages. If packages are not installed in order, and there are file conflicts, then the version chosen depends on the order.
Both ordering issues are avoided if `spack install`/`spack add` and `spack install <spec>` are not mixed.
* Fix bug when system perl is used.
If system perl is being used through packages.yaml there cannot be dependent modules.
The setup_dependent_packages function should not do anything in that case.
When providing a track, the cdash reporter will format the stamp
itself, as it has always done, and register the build during the
package installation process. When providing a stamp, it should
first be formatted as cdash expects, and then cdash will be sure
to report results to same build id which was registered manually
elsewhere.
* Update Spec.prefix to have special case for 'None' in database path; regression test
* Update in database reader rather than spec
* Change assertion to conditional + raise
* Added test for concrete check in Spec.prefix
The module_parsing test checks whether the module function is available
by looking for the string 'not found'. If the user has set a different
locale, the test can assume that the module function is available when
it actually is not.
* Add versions 5.2.0 and 5.1.0
* Avoid adding version 6.0.0: this version has a new API that is
not compatible with older versions (and dependents may break with
it)
* Added comment block explaining the problems with version 6.x
* Replace old datumgrid resource (1.7) with new (1.8)
* Add speculative sqlite dependency for when a 6.x version is added
* add version 7.0.1
* replace md5 with sha256 for various versions.
* v7.0.1 fixes some environment hacking to properly find MPI and
system architecture