diff --git a/var/spack/test_repos/spack_repo/builder_test/packages/inheritance/package.py b/var/spack/test_repos/spack_repo/builder_test/packages/inheritance/package.py
index ab3940d7e76..c9da8c0341f 100644
--- a/var/spack/test_repos/spack_repo/builder_test/packages/inheritance/package.py
+++ b/var/spack/test_repos/spack_repo/builder_test/packages/inheritance/package.py
@@ -3,17 +3,19 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 import os
 
-import spack.pkg.builder_test.callbacks
 from spack.package import *
 
+from ..callbacks.package import Callbacks
+from ..callbacks.package import GenericBuilder as CallbacksGenericBuilder
 
-class Inheritance(spack.pkg.builder_test.callbacks.Callbacks):
+
+class Inheritance(Callbacks):
     """Package used to verify that inheritance among packages work as expected"""
 
     pass
 
 
-class GenericBuilder(spack.pkg.builder_test.callbacks.GenericBuilder):
+class GenericBuilder(CallbacksGenericBuilder):
     def install(self, pkg, spec, prefix):
         super().install(pkg, spec, prefix)
         os.environ["INHERITANCE_INSTALL_CALLED"] = "1"
diff --git a/var/spack/test_repos/spack_repo/builder_test/packages/old_style_derived/package.py b/var/spack/test_repos/spack_repo/builder_test/packages/old_style_derived/package.py
index 0eefa470c9a..8cc3b992a40 100644
--- a/var/spack/test_repos/spack_repo/builder_test/packages/old_style_derived/package.py
+++ b/var/spack/test_repos/spack_repo/builder_test/packages/old_style_derived/package.py
@@ -1,11 +1,12 @@
 # Copyright Spack Project Developers. See COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
-import spack.pkg.builder_test.old_style_autotools
 from spack.package import *
 
+from ..old_style_autotools.package import OldStyleAutotools
 
-class OldStyleDerived(spack.pkg.builder_test.old_style_autotools.OldStyleAutotools):
+
+class OldStyleDerived(OldStyleAutotools):
     """Package used to verify that old-style packages work correctly when executing the
     installation procedure.
     """
diff --git a/var/spack/test_repos/spack_repo/builtin_mock/packages/cmake_client_inheritor/package.py b/var/spack/test_repos/spack_repo/builtin_mock/packages/cmake_client_inheritor/package.py
index e53708d9d3b..d7dd39ff7a8 100644
--- a/var/spack/test_repos/spack_repo/builtin_mock/packages/cmake_client_inheritor/package.py
+++ b/var/spack/test_repos/spack_repo/builtin_mock/packages/cmake_client_inheritor/package.py
@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 from spack.package import *  # noqa: F401
+
 from ..cmake_client.package import CmakeClient
 
 
diff --git a/var/spack/test_repos/spack_repo/builtin_mock/packages/libtool_installation/package.py b/var/spack/test_repos/spack_repo/builtin_mock/packages/libtool_installation/package.py
index 981b5d430af..94e47bf7ed9 100644
--- a/var/spack/test_repos/spack_repo/builtin_mock/packages/libtool_installation/package.py
+++ b/var/spack/test_repos/spack_repo/builtin_mock/packages/libtool_installation/package.py
@@ -2,6 +2,7 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 from spack.package import *
+
 from ..libtool_deletion.package import AutotoolsBuilder as BuilderBase
 from ..libtool_deletion.package import LibtoolDeletion
 
diff --git a/var/spack/test_repos/spack_repo/builtin_mock/packages/maintainers_3/package.py b/var/spack/test_repos/spack_repo/builtin_mock/packages/maintainers_3/package.py
index 539b68692d1..12d59b446b7 100644
--- a/var/spack/test_repos/spack_repo/builtin_mock/packages/maintainers_3/package.py
+++ b/var/spack/test_repos/spack_repo/builtin_mock/packages/maintainers_3/package.py
@@ -2,6 +2,7 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 from spack.package import *
+
 from ..maintainers_1.package import Maintainers1
 
 
diff --git a/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod/package.py b/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod/package.py
index 63be0c03ec1..9c6b2a8dfcd 100644
--- a/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod/package.py
+++ b/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod/package.py
@@ -4,6 +4,7 @@
 
 import spack.platforms
 from spack.package import *
+
 from ..multimethod_base.package import MultimethodBase
 
 
diff --git a/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod_diamond/package.py b/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod_diamond/package.py
index b38d092ac63..407de5c02b6 100644
--- a/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod_diamond/package.py
+++ b/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod_diamond/package.py
@@ -2,9 +2,10 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
+from spack.package import *
+
 from ..multimethod_diamond_parent.package import MultimethodDiamondParent
 from ..multimethod_inheritor.package import MultimethodInheritor
-from spack.package import *
 
 
 class MultimethodDiamond(MultimethodInheritor, MultimethodDiamondParent):
diff --git a/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod_diamond_parent/package.py b/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod_diamond_parent/package.py
index 1dbebeb2839..0d2e8029fcf 100644
--- a/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod_diamond_parent/package.py
+++ b/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod_diamond_parent/package.py
@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 from spack.package import *
+
 from ..multimethod_base.package import MultimethodBase
 
 
diff --git a/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod_inheritor/package.py b/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod_inheritor/package.py
index 7bf9d3f73d3..c45f4634a17 100644
--- a/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod_inheritor/package.py
+++ b/var/spack/test_repos/spack_repo/builtin_mock/packages/multimethod_inheritor/package.py
@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 from spack.package import *
+
 from ..multimethod.package import Multimethod
 
 
diff --git a/var/spack/test_repos/spack_repo/builtin_mock/packages/multimodule_inheritance/package.py b/var/spack/test_repos/spack_repo/builtin_mock/packages/multimodule_inheritance/package.py
index 147d7984309..c36aefa2891 100644
--- a/var/spack/test_repos/spack_repo/builtin_mock/packages/multimodule_inheritance/package.py
+++ b/var/spack/test_repos/spack_repo/builtin_mock/packages/multimodule_inheritance/package.py
@@ -2,9 +2,10 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
-import spack.pkg.builtin_mock.simple_inheritance as si
 from spack.package import *
 
+from ..simple_inheritance import package as si
+
 
 class MultimoduleInheritance(si.BaseWithDirectives):
     """Simple package which inherits a method and several directives"""
diff --git a/var/spack/test_repos/spack_repo/builtin_mock/packages/patch_inheritance/package.py b/var/spack/test_repos/spack_repo/builtin_mock/packages/patch_inheritance/package.py
index 91aff0659cc..03ec9e99de8 100644
--- a/var/spack/test_repos/spack_repo/builtin_mock/packages/patch_inheritance/package.py
+++ b/var/spack/test_repos/spack_repo/builtin_mock/packages/patch_inheritance/package.py
@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 from spack.package import *  # noqa: F401
+
 from ..patch.package import Patch
 
 
diff --git a/var/spack/test_repos/spack_repo/builtin_mock/packages/py_test_callback/package.py b/var/spack/test_repos/spack_repo/builtin_mock/packages/py_test_callback/package.py
index cd2f58f2204..52431bc06b6 100644
--- a/var/spack/test_repos/spack_repo/builtin_mock/packages/py_test_callback/package.py
+++ b/var/spack/test_repos/spack_repo/builtin_mock/packages/py_test_callback/package.py
@@ -3,12 +3,13 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 import spack.builder
-import spack.pkg.builtin_mock.python as mp
 from spack.build_systems._checks import BuilderWithDefaults, execute_install_time_tests
 from spack.package import *
 
+from ..python.package import Python
 
-class PyTestCallback(mp.Python):
+
+class PyTestCallback(Python):
     """A package for testing stand-alone test methods as a callback."""
 
     homepage = "http://www.example.com"
diff --git a/var/spack/test_repos/spack_repo/builtin_mock/packages/variant_values_override/package.py b/var/spack/test_repos/spack_repo/builtin_mock/packages/variant_values_override/package.py
index b2e3773bb03..3cb9ce7e283 100644
--- a/var/spack/test_repos/spack_repo/builtin_mock/packages/variant_values_override/package.py
+++ b/var/spack/test_repos/spack_repo/builtin_mock/packages/variant_values_override/package.py
@@ -2,6 +2,7 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 from spack.package import *
+
 from ..variant_values.package import VariantValues