github spack/spack v0.18.0

one month ago

v0.18.0 (2022-05-28)

v0.18.0 is a major feature release.

Major features in this release

  1. Concretizer now reuses by default

    spack install --reuse was introduced in v0.17.0, and --reuse
    is now the default concretization mode. Spack will try hard to
    resolve dependencies using installed packages or binaries (#30396).

    To avoid reuse and to use the latest package configurations, (the
    old default), you can use spack install --fresh, or add
    configuration like this to your environment or concretizer.yaml:

        reuse: false
  2. Finer-grained hashes

    Spack hashes now include link, run, and build dependencies,
    as well as a canonical hash of package recipes. Previously, hashes
    only included link and run dependencies (though build
    dependencies were stored by environments). We coarsened the hash to
    reduce churn in user installations, but the new default concretizer
    behavior mitigates this concern and gets us reuse and provenance.
    You will be able to see the build dependencies of new installations
    with spack find. Old installations will not change and their
    hashes will not be affected. (#28156, #28504, #30717, #30861)

  3. Improved error messages

    Error handling with the new concretizer is now done with
    optimization criteria rather than with unsatisfiable cores, and
    Spack reports many more details about conflicting constraints.

  4. Unify environments when possible

    Environments have thus far supported concretization: together or
    concretization: separately. These have been replaced by a new
    preference in concretizer.yaml:

        unify: [true|false|when_possible]

    concretizer:unify:when_possible will try to resolve a fully
    unified environment, but if it cannot, it will create multiple
    configurations of some packages where it has to. For large
    environments that previously had to be concretized separately, this
    can result in a huge speedup (40-50x). (#28941)

  5. Automatically find externals on Cray machines

    Spack can now automatically discover installed packages in the Cray
    Programming Environment by running spack external find (or spack external read-cray-manifest to only query the PE). Packages from
    the PE (e.g., cray-mpich are added to the database with full
    dependency information, and compilers from the PE are added to
    compilers.yaml. Available with the June 2022 release of the Cray
    Programming Environment. (#24894, #30428)

  6. New binary format and hardened signing

    Spack now has an updated binary format, with improvements for
    security. The new format has a detached signature file, and Spack
    verifies the signature before untarring or decompressing the binary
    package. The previous format embedded the signature in a tar
    file, which required the client to run tar before verifying
    (#30750). Spack can still install from build caches using the old
    format, but we encourage users to switch to the new format going

    Production GitLab pipelines have been hardened to securely sign
    binaries. There is now a separate signing stage so that signing
    keys are never exposed to build system code, and signing keys are
    ephemeral and only live as long as the signing pipeline stage.

  7. Bootstrap mirror generation

    The spack bootstrap mirror command can automatically create a
    mirror for bootstrapping the concretizer and other needed
    dependencies in an air-gapped environment. (#28556)

  8. Initial Windows support

    Spack now has initial support for Windows. Spack core has been
    refactored to run in the Windows environment, and a small number of
    packages can now build for Windows. More details are
    in the documentation
    (#27021, #28385, many more)

  9. Makefile generation

    spack env depfile can be used to generate a Makefile from an
    environment, which can be used to build packages the environment
    in parallel on a single node. e.g.:

    spack -e myenv env depfile > Makefile

    Spack propagates gmake jobserver information to builds so that
    their jobs can share cores. (#30039, #30254, #30302, #30526)

  10. New variant features

    In addition to being conditional themselves, variants can now have
    conditional values
    that are only possible for certain configurations of a package. (#29530)

    Variants can be
    declared "sticky",
    which prevents them from being enabled or disabled by the
    concretizer. Sticky variants must be set explicitly by users
    on the command line or in packages.yaml. (#28630)

  • Allow conditional possible values in variants
  • Add a "sticky" property to variants

Other new features of note

  • Environment views can optionally link only run dependencies
    with link:run (#29336)
  • spack external find --all finds library-only packages in
    addition to build dependencies (#28005)
  • Customizable config:license_dir option (#30135)
  • spack external find --path PATH takes a custom search path (#30479)
  • spack spec has a new --format argument like spack find (#27908)
  • spack concretize --quiet skips printing concretized specs (#30272)
  • spack info now has cleaner output and displays test info (#22097)
  • Package-level submodule option for git commit versions (#30085, #30037)
  • Using /hash syntax to refer to concrete specs in an environment
    now works even if /hash is not installed. (#30276)

Major internal refactors

  • full hash (see above)
  • new develop versioning scheme 0.19.0-dev0
  • Allow for multiple dependencies/dependents from the same package (#28673)
  • Splice differing virtual packages (#27919)

Performance Improvements

  • Concretization of large environments with unify: when_possible is
    much faster than concretizing separately (#28941, see above)
  • Single-pass view generation algorithm is 2.6x faster (#29443)

Archspec improvements

  • oneapi and dpcpp flag support (#30783)
  • better support for M1 and a64fx (#30683)

Removals and Deprecations

  • Spack no longer supports Python 2.6 (#27256)

  • Removed deprecated --run-tests option of spack install;
    use spack test (#30461)

  • Removed deprecated spack flake8; use spack style (#27290)

  • Deprecate spack:concretization config option; use
    concretizer:unify (#30038)

  • Deprecate top-level module configuration; use module sets (#28659)

  • spack activate and spack deactivate are deprecated in favor of
    environments; will be removed in 0.19.0 (#29430; see also link:run
    in #29336 above)

Notable Bugfixes


  • CMakePackage uses CMAKE_INSTALL_RPATH_USE_LINK_PATH (#29703)
  • Refactored lua support: lua-lang virtual supports both
    lua and luajit via new LuaPackage build system(#28854)
  • PythonPackage: now installs packages with pip (#27798)
  • Python: improve site_packages_dir handling (#28346)
  • Extends: support spec, not just package name (#27754)
  • find_libraries: search for both .so and .dylib on macOS (#28924)
  • Use stable URLs and ?full_index=1 for all github patches (#29239)

Spack community stats

  • 6,416 total packages, 458 new since v0.17.0
    • 219 new Python packages
    • 60 new R packages
  • 377 people contributed to this release
    • 337 committers to packages
    • 85 committers to core

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