NWChemEx Spack Package Repositories

WARNING: Under heavy construction and subject to change at any moment. Not ready for use yet!

Installation

Spack >=1.0.0:

Spack versions >=1.0.0 support cloning GitHub repositories with potentially multiple Spack repositories inside. This is the easiest method to fetch and add the Spack repositories here.

# Clone the repo into '~/.spack/package_repos/<hashed_name>'
spack repo add --name nwchemex https://github.com/NWChemEx/SpackRepos.git
# Or, to choose the destination
spack repo add --name nwchemex https://github.com/NWChemEx/SpackRepos.git <destination>

Spack <1.0.0

In pre-1.0.0 Spack releases, GitHub-hosted package repositories need to be downloaded and added manually.

# Clone the repo into your <desired_directory>
git clone https://github.com/NWChemEx/SpackRepos.git <desired_directory>

# Add desired NWChemEx Spack repos
spack repo add <desired_directory>/spack_repo/nwchemex/core
spack repo add <desired_directory>/spack_repo/nwchemex/overrides
# ... other sub-repos ...

Updating

Spack >1.0.0

As of Spack v1.0.0, there is no automatic update mechanism for Git-based repos in Spack. They recommend doing so manually with the following commands:

# Navigate to the repo directory
spack cd --repo nwchemex

# Pull the latest changes from GitHub
git pull
# Or checkout a specific commit or version tag
git checkout <commit|tag>

Spack <1.0.0

Updating with Spack <1.0.0 is approximately the same as >=1.0.0, and must be done by manually updating the cloned GitHub repository. The following commands will update all nwchemex.* sub-repos at once. You do not need to run this separately for each nwchemex.* sub-repo!

# Navigate to the repo directory
# (any nwchemex.* sub-repo can be used here in place of nwchemex.core)
spack cd --repo nwchemex.core

# Pull the latest changes from GitHub
git pull
# Or checkout a specific commit or version tag
git checkout <commit|tag>

Usage

Namespacing

This GitHub repository provides various package repositories for the NWChemEx project under an nwchemex organization-level namespace with the following structure:

spack_repo
└── nwchemex
    ├── core
    │   ├── packages
    │   │   ├── package_1
    │   │   ├── package_2
    │   │   └── ... more packages ...
    │   └── repo.yaml
    ├── overrides
    │   ├── packages
    │   │   └── ...
    │   └── repo.yaml
    └── another_repo
        ├── packages
        │   └── ...
        └── repo.yaml

In Spack, package repositories are namespaced as nwchemex.<sub_repo_name> and are defined on disk as spack_repo/nwchemex/<sub_repo_name>/. The current package repositories can be found inside spack_subrepo/nwchemex/.

Packages can be distinguished by prefixing the package name with the package repository namespace it is defined in (e.g. nwchemex.repo_a.package_1). This is useful to determine from which repository a package originated, like to confirm that you are using the correct override of a package. However, in general, namespaces are not needed when identifying a package in a package specification and should be avoided. Spack actually strongly discourages using explicit namespacing in depends_on() statements of packages, as "It makes the package non-portable and tightly coupled to a specific repository configuration, hindering sharing and composition of repositories." (see warning at the bottom of Spack's Search Order and Overriding Packages).

nwchemex.core

Spack package repository for core (first-party) packages in the NWChemEx software stack.

nwchemex.overrides

Spack package repository to override existing packages for use in NWChemEx software stack.

For packages in the nwchemex.overrides repository to work once installed, nwchemex.overrides must be listed above the repository whose package it is overriding in repos.yaml or the repos: section of an environment spack.yaml. The correct file can be opened for updating with:

spack config edit repos

For more information, see the Spack's Search Order and Overriding Packages.

Helpful Spack Commands

For a broader list of helpful Spack repository management commands, see Spack's The spack repo Command.