 Todd Gamblin
		
	
	5f073ae220
	
	
	More spec improvements
			Todd Gamblin
		
	
	5f073ae220
	
	
	More spec improvements
		
			
			- Spec.copy() does not create superfluous nodes and preserves DAG
  connections.
- Spec.normalize() doesn't create extra dependency nodes or throw out
  old ones like before.
- Added better test cases for above changes.
Minor things:
- Fixed bug waiting to happen in PackageDB.get()
  - instances was keyed by name, not by spec, so caching wasn't really
    working at all.
- removed unused PackageDB.compute_dependents function.
- Fixed PackageDB.graph_dependencies() so that spack graph works again.
		
	
Spack
Spack is a package management tool designed to support multiple versions and configurations of software on a wide variety of platforms and environments. It was designed for large supercomputing centers, where many users and application teams share common installations of software on clusters with exotic architectures, using libraries that do not have a standard ABI. Spack is non-destructive: installing a new version does not break existing installations, so many configurations can coexist on the same system.
Most importantly, Spack is simple. It offers a simple spec syntax so that users can specify versions and configuration options concisely. Spack is also simple for package authors: package files are writtin in pure Python, and specs allow package authors to write a single build script for many different builds of the same package.
See the Feature Overview for examples and highlights.
To install spack and install your first package:
$ git clone git@github.com:scalability-llnl/spack.git
$ cd spack/bin
$ ./spack install libelf
Documentation
Full documentation for Spack is also available.
Authors
Spack was written by Todd Gamblin, tgamblin@llnl.gov. LLNL-CODE-647188