$ spack install --help
usage: spack install [-h] [-i] [-j JOBS] [--keep-prefix] [--keep-stage] [-n]
                     [-v] [--fake] [--dirty] [--run-tests]
                     ...

positional arguments:
--->  packages              specs of packages to install <---

optional arguments:
  -h, --help            show this help message and exit
  -i, --ignore-dependencies
                        Do not try to install dependencies of requested
                        packages.
  -j JOBS, --jobs JOBS  Explicitly set number of make jobs. Default is #cpus.
  --keep-prefix         Don't remove the install prefix if installation fails.
  --keep-stage          Don't remove the build stage if installation succeeds.
  -n, --no-checksum     Do not check packages against checksum
  -v, --verbose         Display verbose build output while installing.
  --fake                Fake install. Just remove the prefix and touch a fake
                        file in it.
  --dirty               Install a package *without* cleaning the environment.
  --run-tests           Run tests during installation of a package.

$ spack install openjpeg zlib
==> Error: There are no valid versions for openjpeg that match ''