diff --git a/packages/arbor/package.py b/packages/arbor/package.py
index c9d1e1e1c9d0837ee75afa0d1fcb7268505e8406..56791d87b3bfa8f2bfc8addb4174eeda5f9564ce 100644
--- a/packages/arbor/package.py
+++ b/packages/arbor/package.py
@@ -3,81 +3,109 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
-from spack import *
+from spack.package import *
 
 
 class Arbor(CMakePackage, CudaPackage):
     """Arbor is a high-performance library for computational neuroscience
     simulations."""
 
-    homepage = 'https://arbor-sim.org'
-    git      = 'https://github.com/arbor-sim/arbor.git'
-    url      = 'https://github.com/arbor-sim/arbor/releases/download/v0.6/arbor-v0.6-full.tar.gz'
-    maintainers = ['bcumming', 'brenthuisman', 'haampie', 'schmitts']
-
-    version('master', branch='master', submodules=True)
-    version('0.6', sha256='4cd333b18effc8833428ddc0b99e7dc976804771bc85da90034c272c7019e1e8', url='https://github.com/arbor-sim/arbor/releases/download/v0.6/arbor-v0.6-full.tar.gz')
-    version('0.5.2', sha256='290e2ad8ca8050db1791cabb6b431e7c0409c305af31b559e397e26b300a115d', url='https://github.com/arbor-sim/arbor/releases/download/v0.5.2/arbor-v0.5.2-full.tar.gz')
-    version('0.5', sha256='d0c8a4c7f97565d7c30493c66249be794d1dc424de266fc79cecbbf0e313df59', url='https://github.com/arbor-sim/arbor/releases/download/v0.5/arbor-v0.5-full.tar.gz')
-
-    variant('assertions', default=False, description='Enable arb_assert() assertions in code.')
-    variant('doc', default=False, description='Build documentation.')
-    variant('mpi', default=False, description='Enable MPI support')
-    variant('neuroml', default=True, description='Build NeuroML support library.')
-    variant('python', default=True, description='Enable Python frontend support')
-    variant('vectorize', default=False, description='Enable vectorization of computational kernels')
-
-    # https://docs.arbor-sim.org/en/latest/install/build_install.html?highlight=requirements#compilers
-    conflicts('%gcc@:8.3')
-    conflicts('%clang@:7')
+    homepage = "https://arbor-sim.org"
+    git = "https://github.com/arbor-sim/arbor.git"
+    url = "https://github.com/arbor-sim/arbor/releases/download/v0.7/arbor-v0.7-full.tar.gz"
+    maintainers = ["bcumming", "brenthuisman", "haampie", "schmitts"]
+
+    version("master", branch="master", submodules=True)
+    version(
+        "0.7",
+        sha256="c3a6b7193946aee882bb85f9c38beac74209842ee94e80840968997ba3b84543",
+        url="https://github.com/arbor-sim/arbor/releases/download/v0.7/arbor-v0.7-full.tar.gz",
+    )
+    version(
+        "0.6",
+        sha256="4cd333b18effc8833428ddc0b99e7dc976804771bc85da90034c272c7019e1e8",
+        url="https://github.com/arbor-sim/arbor/releases/download/v0.6/arbor-v0.6-full.tar.gz",
+    )
+    version(
+        "0.5.2",
+        sha256="290e2ad8ca8050db1791cabb6b431e7c0409c305af31b559e397e26b300a115d",
+        url="https://github.com/arbor-sim/arbor/releases/download/v0.5.2/arbor-v0.5.2-full.tar.gz",
+    )
+    version(
+        "0.5",
+        sha256="d0c8a4c7f97565d7c30493c66249be794d1dc424de266fc79cecbbf0e313df59",
+        url="https://github.com/arbor-sim/arbor/releases/download/v0.5/arbor-v0.5-full.tar.gz",
+    )
+
+    variant(
+        "assertions",
+        default=False,
+        description="Enable arb_assert() assertions in code.",
+    )
+    variant("doc", default=False, description="Build documentation.")
+    variant("mpi", default=False, description="Enable MPI support")
+    variant("neuroml", default=True, description="Build NeuroML support library.")
+    variant("python", default=True, description="Enable Python frontend support")
+    variant(
+        "vectorize",
+        default=False,
+        description="Enable vectorization of computational kernels",
+    )
+
+    # https://docs.arbor-sim.org/en/latest/install/build_install.html#compilers
+    conflicts("%gcc@:8.3")
+    conflicts("%clang@:7")
     # Cray compiler v9.2 and later is Clang-based.
-    conflicts('%cce@:9.1')
-    conflicts('%intel')
+    conflicts("%cce@:9.1")
+    conflicts("%intel")
 
-    depends_on('cmake@3.12:', type='build')
+    depends_on("cmake@3.12:", type="build")
 
     # misc dependencies
-    depends_on('fmt@7.1:', when='@0.5.3:') # required by the modcc compiler
-    depends_on('nlohmann-json')
-    depends_on('cuda@10:', when='+cuda')
-    depends_on('libxml2', when='+neuroml')
+    depends_on("fmt@7.1:", when="@0.5.3:")  # required by the modcc compiler
+    depends_on("nlohmann-json")
+    depends_on("random123")
+    depends_on("cuda@10:", when="+cuda")
+    depends_on("libxml2", when="+neuroml")
 
     # mpi
-    depends_on('mpi', when='+mpi')
-    depends_on('py-mpi4py', when='+mpi+python', type=('build', 'run'))
+    depends_on("mpi", when="+mpi")
+    depends_on("py-mpi4py", when="+mpi+python", type=("build", "run"))
 
     # python (bindings)
-    extends('python', when='+python')
-    depends_on('python@3.6:', when="+python", type=('build', 'run'))
-    depends_on('py-numpy', when='+python', type=('build', 'run'))
-    depends_on('py-pybind11@2.8.1:', when='+python', type=('build', 'run'))
+    extends("python", when="+python")
+    depends_on("python@3.7:", when="+python", type=("build", "run"))
+    depends_on("py-numpy", when="+python", type=("build", "run"))
+    with when("+python"):
+        depends_on("py-pybind11@2.6:", type=("build"))
+        depends_on("py-pybind11@2.8.1:", when="@0.5.3:", type=("build"))
 
     # sphinx based documentation
-    depends_on('python@3.6:', when="+doc", type='build')
-    depends_on('py-sphinx', when="+doc", type='build')
-    depends_on('py-svgwrite', when='+doc', type='build')
+    depends_on("python@3.7:", when="+doc", type="build")
+    depends_on("py-sphinx", when="+doc", type="build")
+    depends_on("py-svgwrite", when="+doc", type="build")
 
     @property
     def build_targets(self):
-        return ['all', 'html'] if '+doc' in self.spec else ['all']
+        return ["all", "html"] if "+doc" in self.spec else ["all"]
 
     def cmake_args(self):
         args = [
-            self.define_from_variant('ARB_WITH_ASSERTIONS', 'assertions'),
-            self.define_from_variant('ARB_WITH_MPI', 'mpi'),
-            self.define_from_variant('ARB_WITH_NEUROML', 'neuroml'),
-            self.define_from_variant('ARB_WITH_PYTHON', 'python'),
-            self.define_from_variant('ARB_VECTORIZE', 'vectorize'),
+            self.define_from_variant("ARB_WITH_ASSERTIONS", "assertions"),
+            self.define_from_variant("ARB_WITH_MPI", "mpi"),
+            self.define_from_variant("ARB_WITH_NEUROML", "neuroml"),
+            self.define_from_variant("ARB_WITH_PYTHON", "python"),
+            self.define_from_variant("ARB_VECTORIZE", "vectorize"),
         ]
 
-        if '+cuda' in self.spec:
-            args.append('-DARB_GPU=cuda')
+        if "+cuda" in self.spec:
+            args.append("-DARB_GPU=cuda")
 
         # query spack for the architecture-specific compiler flags set by its wrapper
-        args.append('-DARB_ARCH=none')
+        args.append("-DARB_ARCH=none")
         opt_flags = self.spec.target.optimization_flags(
-            self.spec.compiler.name,
-            self.spec.compiler.version)
-        args.append('-DARB_CXX_FLAGS_TARGET=' + opt_flags)
+            self.spec.compiler.name, self.spec.compiler.version
+        )
+        args.append("-DARB_CXX_FLAGS_TARGET=" + opt_flags)
 
         return args