Use spack to download some source code

download.py

#!/usr/bin/env spack-python

import os
import tempfile
from spack.spec import Spec
from spack.stage import DIYStage
import llnl.util.filesystem as fs

# concrtize a spec of what you want to build.
spec = Spec("hdf5 @1.10.2").concretized()

# the package instance, instantiate with spec, is essentially a class for
# "building" the spec with the package.py recipe.
pkg = spec.package

# set the staging path (this makes all stages download to a new path)
# note that there are potentially many stages for a package -- for the
# archive, patches, and any resources (extra tarballs) that need to be
# downloaded -- those are in pkg.stage[0], pkg.stage[1], etc.
pkg.path = os.path.abspath("foo")

# omit this contextmanager and call pkg.stage.destroy() manually if you
# don't want the stage automatically destroyed.
with pkg.stage:

    # this fetches (if not fetched already) and expands the source into a
    # stage directory. You may want to call do_patch() instead (or later)
    # if you want patches applied to the source.
    pkg.do_stage()

    # this contextmanager does a chdir into the directory and
    # automatically chdirs back out.
    with fs.working_dir(pkg.stage.source_path) as path:
        # do stuff in the checked out source path
        print(path)
        print(os.getcwd())
        print(os.listdir())