diff --git a/.github/workflows/ci-units-types.yml b/.github/workflows/ci-units-types.yml
index bb70be5aa93..00c2e6d846e 100644
--- a/.github/workflows/ci-units-types.yml
+++ b/.github/workflows/ci-units-types.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
 
     steps:
       - uses: actions/checkout@v3
diff --git a/kiwi/builder/install.py b/kiwi/builder/install.py
index 23d424fd4c1..42215542205 100644
--- a/kiwi/builder/install.py
+++ b/kiwi/builder/install.py
@@ -280,9 +280,9 @@ def create_install_pxe_archive(self) -> None:
             source_filename=self.diskname,
             keep_source_on_compress=True
         )
-        compress.xz(self.xz_options)
+        xz_archive = compress.xz(self.xz_options)
         Command.run(
-            ['mv', compress.compressed_filename, pxe_image_filename]
+            ['mv', xz_archive, pxe_image_filename]
         )
 
         # the system image transfer is checked against a checksum
diff --git a/kiwi/command.py b/kiwi/command.py
index 057ea610350..95e68a3f7dc 100644
--- a/kiwi/command.py
+++ b/kiwi/command.py
@@ -15,11 +15,17 @@
 # You should have received a copy of the GNU General Public License
 # along with kiwi.  If not, see <http://www.gnu.org/licenses/>
 #
-from typing import NamedTuple
-import select
-import os
+from typing import IO, Callable, List, MutableMapping, NamedTuple, Optional, overload
 import logging
+import os
+import select
 import subprocess
+import sys
+
+if sys.version_info >= (3, 8):
+    from typing import Literal  # pragma: no cover
+else:  # pragma: no cover
+    from typing_extensions import Literal  # pragma: no cover
 
 # project
 from kiwi.utils.codec import Codec
@@ -31,23 +37,19 @@
 
 log = logging.getLogger('kiwi')
 
-command_type = NamedTuple(
-    'command_type', [
-        ('output', str),
-        ('error', str),
-        ('returncode', int)
-    ]
-)
 
-command_call_type = NamedTuple(
-    'command_call_type', [
-        ('output', str),
-        ('output_available', bool),
-        ('error', str),
-        ('error_available', bool),
-        ('process', subprocess.Popen)
-    ]
-)
+class CommandT(NamedTuple):
+    output: str
+    error: str
+    returncode: int
+
+
+class CommandCallT(NamedTuple):
+    output: IO[bytes]
+    output_available: Callable[[], bool]
+    error: IO[bytes]
+    error_available: Callable[[], bool]
+    process: subprocess.Popen
 
 
 class Command:
@@ -58,16 +60,39 @@ class Command:
     commands in blocking and non blocking mode. Control of
     stdout and stderr is given to the caller
     """
+
+    @overload
+    @staticmethod
+    def run(
+        command: List[str], custom_env: Optional[MutableMapping[str, str]] = None,
+        raise_on_error: bool = True, stderr_to_stdout: bool = False,
+        raise_on_command_not_found: Literal[False] = False
+    ) -> CommandT:
+        ...  # pragma: no cover
+
+    @overload
+    @staticmethod
+    def run(
+        command: List[str], custom_env: Optional[MutableMapping[str, str]] = None,
+        raise_on_error: bool = True, stderr_to_stdout: bool = False,
+        raise_on_command_not_found: bool = True
+    ) -> Optional[CommandT]:
+        ...  # pragma: no cover
+
     @staticmethod
     def run(
-        command, custom_env=None, raise_on_error=True, stderr_to_stdout=False
-    ):
+        command: List[str], custom_env: Optional[MutableMapping[str, str]] = None,
+        raise_on_error: bool = True, stderr_to_stdout: bool = False,
+        raise_on_command_not_found: bool = True
+    ) -> Optional[CommandT]:
         """
         Execute a program and block the caller. The return value
-        is a hash containing the stdout, stderr and return code
-        information. Unless raise_on_error is set to false an
-        exception is thrown if the command exits with an error
-        code not equal to zero
+        is a CommandT namedtuple containing the stdout, stderr
+        and return code information. Unless raise_on_error is
+        set to `False` an exception is thrown if the command
+        exits with an error code not equal to zero. If
+        raise_on_command_not_found is `False` and the command is
+        not found, then `None` is returned.
 
         Example:
 
@@ -76,7 +101,7 @@ def run(
             result = Command.run(['ls', '-l'])
 
         :param list command: command and arguments
-        :param list custom_env: custom os.environ
+        :param dict custom_env: custom os.environ
         :param bool raise_on_error: control error behaviour
         :param bool stderr_to_stdout: redirects stderr to stdout
 
@@ -85,40 +110,42 @@ def run(
 
             .. code:: python
 
-                command(output='string', error='string', returncode=int)
+                CommandT(output='string', error='string', returncode=int)
 
-        :rtype: namedtuple
+        :rtype: CommandT
         """
         from .path import Path
         log.debug('EXEC: [%s]', ' '.join(command))
-        environment = os.environ
-        if custom_env:
-            environment = custom_env
-        if not Path.which(
-            command[0], custom_env=environment, access_mode=os.X_OK
-        ):
+        environment = custom_env or os.environ
+        cmd_abspath: Optional[str]
+        if command[0].startswith("/"):
+            cmd_abspath = command[0]
+            if not os.path.exists(cmd_abspath):
+                cmd_abspath = None
+        else:
+            cmd_abspath = Path.which(
+                command[0], custom_env=environment, access_mode=os.X_OK
+            )
+
+        if not cmd_abspath:
             message = 'Command "%s" not found in the environment' % command[0]
-            if not raise_on_error:
-                log.debug('EXEC: %s', message)
-                return command_type(
-                    output=None,
-                    error=None,
-                    returncode=-1
-                )
-            else:
+            if raise_on_command_not_found:
                 raise KiwiCommandNotFound(message)
+            log.debug('EXEC: %s', message)
+            return None
         stderr = subprocess.STDOUT if stderr_to_stdout else subprocess.PIPE
         try:
             process = subprocess.Popen(
-                command,
+                [cmd_abspath] + command[1:],
                 stdout=subprocess.PIPE,
                 stderr=stderr,
                 env=environment
             )
-        except Exception as e:
+        except (OSError, subprocess.SubprocessError) as e:
             raise KiwiCommandError(
                 '%s: %s: %s' % (command[0], type(e).__name__, format(e))
-            )
+            ) from e
+
         output, error = process.communicate()
         if process.returncode != 0 and raise_on_error:
             if not error:
@@ -135,14 +162,17 @@ def run(
                     command[0], Codec.decode(error), Codec.decode(output)
                 )
             )
-        return command_type(
+        return CommandT(
             output=Codec.decode(output),
             error=Codec.decode(error),
             returncode=process.returncode
         )
 
     @staticmethod
-    def call(command, custom_env=None):
+    def call(
+            command: List[str],
+            custom_env: Optional[MutableMapping[str, str]] = None
+    ) -> CommandCallT:
         """
         Execute a program and return an io file handle pair back.
         stdout and stderr are both on different channels. The caller
@@ -174,9 +204,7 @@ def call(command, custom_env=None):
         """
         from .path import Path
         log.debug('EXEC: [%s]', ' '.join(command))
-        environment = os.environ
-        if custom_env:
-            environment = custom_env
+        environment = custom_env or os.environ
         if not Path.which(
             command[0], custom_env=environment, access_mode=os.X_OK
         ):
@@ -193,31 +221,32 @@ def call(command, custom_env=None):
         except Exception as e:
             raise KiwiCommandError(
                 '%s: %s' % (type(e).__name__, format(e))
-            )
+            ) from e
+
+        # guaranteed to be true as stdout & stderr equal subprocess.PIPE
+        assert process.stdout and process.stderr
 
-        def output_available():
+        def output_available() -> Callable[[], bool]:
             def _select():
-                descriptor_lists = select.select(
+                readable, _, exceptional = select.select(
                     [process.stdout], [], [process.stdout], 1e-4
                 )
-                readable = descriptor_lists[0]
-                exceptional = descriptor_lists[2]
                 if readable and not exceptional:
                     return True
+                return False
             return _select
 
-        def error_available():
+        def error_available() -> Callable[[], bool]:
             def _select():
-                descriptor_lists = select.select(
+                readable, _, exceptional = select.select(
                     [process.stderr], [], [process.stderr], 1e-4
                 )
-                readable = descriptor_lists[0]
-                exceptional = descriptor_lists[2]
                 if readable and not exceptional:
                     return True
+                return False
             return _select
 
-        return command_call_type(
+        return CommandCallT(
             output=process.stdout,
             output_available=output_available(),
             error=process.stderr,
diff --git a/kiwi/command_process.py b/kiwi/command_process.py
index 45e6a876951..42d0680918c 100644
--- a/kiwi/command_process.py
+++ b/kiwi/command_process.py
@@ -17,6 +17,7 @@
 #
 import logging
 from collections import namedtuple
+from kiwi.command import CommandCallT
 
 # project
 from kiwi.utils.codec import Codec
@@ -37,7 +38,7 @@ class CommandProcess:
     :param subprocess command: instance of subprocess
     :param string log_topic: topic string for logging
     """
-    def __init__(self, command, log_topic='system'):
+    def __init__(self, command: CommandCallT, log_topic='system') -> None:
         self.command = CommandIterator(command)
         self.log_topic = log_topic
         self.items_processed = 0
@@ -154,7 +155,7 @@ class CommandIterator:
 
     :param subprocess command: instance of subprocess
     """
-    def __init__(self, command):
+    def __init__(self, command: CommandCallT) -> None:
         self.command = command
         self.command_error_output = bytes(b'')
         self.command_output_line = bytes(b'')
@@ -196,7 +197,7 @@ def get_error_output(self):
         """
         return Codec.decode(self.command_error_output)
 
-    def get_error_code(self):
+    def get_error_code(self) -> int:
         """
         Provide return value from processed command
 
@@ -206,7 +207,7 @@ def get_error_code(self):
         """
         return self.command.process.returncode
 
-    def get_pid(self):
+    def get_pid(self) -> int:
         """
         Provide process ID of command while running
 
@@ -216,7 +217,7 @@ def get_pid(self):
         """
         return self.command.process.pid
 
-    def kill(self):
+    def kill(self) -> None:
         """
         Send kill signal SIGTERM to command process
         """
diff --git a/kiwi/mount_manager.py b/kiwi/mount_manager.py
index fc6d0314d86..15377cf9537 100644
--- a/kiwi/mount_manager.py
+++ b/kiwi/mount_manager.py
@@ -216,7 +216,4 @@ def is_mounted(self) -> bool:
             command=['mountpoint', '-q', self.mountpoint],
             raise_on_error=False
         )
-        if mountpoint_call.returncode == 0:
-            return True
-        else:
-            return False
+        return mountpoint_call.returncode == 0
diff --git a/kiwi/package_manager/apt.py b/kiwi/package_manager/apt.py
index 535e511769a..a87abf3fea5 100644
--- a/kiwi/package_manager/apt.py
+++ b/kiwi/package_manager/apt.py
@@ -24,7 +24,7 @@
 )
 
 # project
-from kiwi.command import command_call_type
+from kiwi.command import CommandCallT
 from kiwi.command import Command
 from kiwi.path import Path
 from kiwi.package_manager.base import PackageManagerBase
@@ -128,7 +128,7 @@ def setup_repository_modules(
 
     def process_install_requests_bootstrap(
         self, root_bind: RootBind = None, bootstrap_package: str = None
-    ) -> command_call_type:
+    ) -> CommandCallT:
         """
         Process package install requests for bootstrap phase (no chroot)
         Either debootstrap or a prebuilt bootstrap package can be used
@@ -155,7 +155,7 @@ def process_install_requests_bootstrap(
 
     def _process_install_requests_bootstrap_prebuild_root(
         self, bootstrap_package: str
-    ) -> command_call_type:
+    ) -> CommandCallT:
         """
         Process bootstrap phase (no chroot) using a prebuilt bootstrap
         package. The package has to provide a tarball below the
@@ -207,7 +207,7 @@ def _process_install_requests_bootstrap_prebuild_root(
 
     def _process_install_requests_bootstrap_debootstrap(
         self, root_bind: RootBind = None
-    ) -> command_call_type:
+    ) -> CommandCallT:
         """
         Process package install requests for bootstrap phase (no chroot)
         The debootstrap program is used to bootstrap a new system
@@ -316,7 +316,7 @@ def post_process_install_requests_bootstrap(
         if root_bind:
             root_bind.mount_kernel_file_systems(delta_root)
 
-    def process_install_requests(self) -> command_call_type:
+    def process_install_requests(self) -> CommandCallT:
         """
         Process package install requests for image phase (chroot)
 
@@ -344,7 +344,7 @@ def process_install_requests(self) -> command_call_type:
             apt_get_command, self.command_env
         )
 
-    def process_delete_requests(self, force: bool = False) -> command_call_type:
+    def process_delete_requests(self, force: bool = False) -> CommandCallT:
         """
         Process package delete requests (chroot)
 
@@ -452,7 +452,7 @@ def post_process_delete_requests(
             ]
         )
 
-    def update(self) -> command_call_type:
+    def update(self) -> CommandCallT:
         """
         Process package update requests (chroot)
 
diff --git a/kiwi/package_manager/base.py b/kiwi/package_manager/base.py
index a7a01d1e110..4567000d228 100644
--- a/kiwi/package_manager/base.py
+++ b/kiwi/package_manager/base.py
@@ -20,7 +20,7 @@
 )
 
 from kiwi.api_helper import decommissioned
-from kiwi.command import command_call_type
+from kiwi.command import CommandCallT
 from kiwi.system.root_bind import RootBind
 from kiwi.repository.base import RepositoryBase
 
@@ -117,7 +117,7 @@ def setup_repository_modules(
 
     def process_install_requests_bootstrap(
         self, root_bind: RootBind = None, bootstrap_package: str = None
-    ) -> command_call_type:
+    ) -> CommandCallT:
         """
         Process package install requests for bootstrap phase (no chroot)
 
@@ -125,7 +125,7 @@ def process_install_requests_bootstrap(
         """
         raise NotImplementedError
 
-    def process_install_requests(self) -> command_call_type:
+    def process_install_requests(self) -> CommandCallT:
         """
         Process package install requests for image phase (chroot)
 
@@ -133,7 +133,7 @@ def process_install_requests(self) -> command_call_type:
         """
         raise NotImplementedError
 
-    def process_delete_requests(self, force: bool = False) -> command_call_type:
+    def process_delete_requests(self, force: bool = False) -> CommandCallT:
         """
         Process package delete requests (chroot)
 
@@ -143,7 +143,7 @@ def process_delete_requests(self, force: bool = False) -> command_call_type:
         """
         raise NotImplementedError
 
-    def update(self) -> command_call_type:
+    def update(self) -> CommandCallT:
         """
         Process package update requests (chroot)
 
@@ -243,7 +243,7 @@ def has_failed(returncode: int) -> bool:
 
         :rtype: boolean
         """
-        return True if returncode != 0 else False
+        return returncode != 0
 
     def get_error_details(self) -> str:
         """
diff --git a/kiwi/package_manager/dnf.py b/kiwi/package_manager/dnf.py
index 248b032afa9..8e0b7631582 100644
--- a/kiwi/package_manager/dnf.py
+++ b/kiwi/package_manager/dnf.py
@@ -20,7 +20,7 @@
 )
 
 # project
-from kiwi.command import command_call_type
+from kiwi.command import CommandCallT
 from kiwi.package_manager.base import PackageManagerBase
 from kiwi.system.root_bind import RootBind
 from kiwi.api_helper import decommissioned
@@ -60,22 +60,22 @@ def setup_repository_modules(
     @decommissioned
     def process_install_requests_bootstrap(
         self, root_bind: RootBind = None, bootstrap_package: str = None
-    ) -> command_call_type:
+    ) -> CommandCallT:
         pass  # pragma: no cover
 
     @no_type_check
     @decommissioned
-    def process_install_requests(self) -> command_call_type:
+    def process_install_requests(self) -> CommandCallT:
         pass  # pragma: no cover
 
     @no_type_check
     @decommissioned
-    def process_delete_requests(self, force: bool = False) -> command_call_type:
+    def process_delete_requests(self, force: bool = False) -> CommandCallT:
         pass  # pragma: no cover
 
     @no_type_check
     @decommissioned
-    def update(self) -> command_call_type:
+    def update(self) -> CommandCallT:
         pass  # pragma: no cover
 
     @decommissioned
diff --git a/kiwi/package_manager/dnf4.py b/kiwi/package_manager/dnf4.py
index 10395fe43e3..18599d41fe4 100644
--- a/kiwi/package_manager/dnf4.py
+++ b/kiwi/package_manager/dnf4.py
@@ -21,7 +21,7 @@
 )
 
 # project
-from kiwi.command import command_call_type
+from kiwi.command import CommandCallT
 from kiwi.command import Command
 from kiwi.utils.rpm_database import RpmDataBase
 from kiwi.utils.rpm import Rpm
@@ -136,7 +136,7 @@ def setup_repository_modules(
 
     def process_install_requests_bootstrap(
         self, root_bind: RootBind = None, bootstrap_package: str = None
-    ) -> command_call_type:
+    ) -> CommandCallT:
         """
         Process package install requests for bootstrap phase (no chroot)
 
@@ -165,7 +165,7 @@ def process_install_requests_bootstrap(
             dnf_command, self.command_env
         )
 
-    def process_install_requests(self) -> command_call_type:
+    def process_install_requests(self) -> CommandCallT:
         """
         Process package install requests for image phase (chroot)
 
@@ -196,7 +196,7 @@ def process_install_requests(self) -> command_call_type:
             dnf_command, self.command_env
         )
 
-    def process_delete_requests(self, force: bool = False) -> command_call_type:
+    def process_delete_requests(self, force: bool = False) -> CommandCallT:
         """
         Process package delete requests (chroot)
 
@@ -245,7 +245,7 @@ def process_delete_requests(self, force: bool = False) -> command_call_type:
                 dnf_command, self.command_env
             )
 
-    def update(self) -> command_call_type:
+    def update(self) -> CommandCallT:
         """
         Process package update requests (chroot)
 
diff --git a/kiwi/package_manager/dnf5.py b/kiwi/package_manager/dnf5.py
index 56ce89ddc2d..3be05d1e83c 100644
--- a/kiwi/package_manager/dnf5.py
+++ b/kiwi/package_manager/dnf5.py
@@ -21,7 +21,7 @@
 )
 
 # project
-from kiwi.command import command_call_type
+from kiwi.command import CommandCallT
 from kiwi.command import Command
 from kiwi.utils.rpm_database import RpmDataBase
 from kiwi.utils.rpm import Rpm
@@ -136,7 +136,7 @@ def setup_repository_modules(
 
     def process_install_requests_bootstrap(
         self, root_bind: RootBind = None, bootstrap_package: str = None
-    ) -> command_call_type:
+    ) -> CommandCallT:
         """
         Process package install requests for bootstrap phase (no chroot)
 
@@ -165,7 +165,7 @@ def process_install_requests_bootstrap(
             dnf_command, self.command_env
         )
 
-    def process_install_requests(self) -> command_call_type:
+    def process_install_requests(self) -> CommandCallT:
         """
         Process package install requests for image phase (chroot)
 
@@ -196,7 +196,7 @@ def process_install_requests(self) -> command_call_type:
             dnf_command, self.command_env
         )
 
-    def process_delete_requests(self, force: bool = False) -> command_call_type:
+    def process_delete_requests(self, force: bool = False) -> CommandCallT:
         """
         Process package delete requests (chroot)
 
@@ -245,7 +245,7 @@ def process_delete_requests(self, force: bool = False) -> command_call_type:
                 dnf_command, self.command_env
             )
 
-    def update(self) -> command_call_type:
+    def update(self) -> CommandCallT:
         """
         Process package update requests (chroot)
 
diff --git a/kiwi/package_manager/microdnf.py b/kiwi/package_manager/microdnf.py
index b783fe6348b..2636d56a329 100644
--- a/kiwi/package_manager/microdnf.py
+++ b/kiwi/package_manager/microdnf.py
@@ -23,7 +23,7 @@
 
 
 # project
-from kiwi.command import command_call_type
+from kiwi.command import CommandCallT
 from kiwi.command import Command
 from kiwi.utils.rpm_database import RpmDataBase
 from kiwi.utils.rpm import Rpm
@@ -155,7 +155,7 @@ def setup_repository_modules(
 
     def process_install_requests_bootstrap(
         self, root_bind: RootBind = None, bootstrap_package: str = None
-    ) -> command_call_type:
+    ) -> CommandCallT:
         """
         Process package install requests for bootstrap phase (no chroot)
 
@@ -187,7 +187,7 @@ def process_install_requests_bootstrap(
             microdnf_command, self.command_env
         )
 
-    def process_install_requests(self) -> command_call_type:
+    def process_install_requests(self) -> CommandCallT:
         """
         Process package install requests for image phase (chroot)
 
@@ -218,7 +218,7 @@ def process_install_requests(self) -> command_call_type:
             microdnf_command, self.command_env
         )
 
-    def process_delete_requests(self, force: bool = False) -> command_call_type:
+    def process_delete_requests(self, force: bool = False) -> CommandCallT:
         """
         Process package delete requests (chroot)
 
@@ -267,7 +267,7 @@ def process_delete_requests(self, force: bool = False) -> command_call_type:
                 dnf_command, self.command_env
             )
 
-    def update(self) -> command_call_type:
+    def update(self) -> CommandCallT:
         """
         Process package update requests (chroot)
 
diff --git a/kiwi/package_manager/pacman.py b/kiwi/package_manager/pacman.py
index 95c68675f17..be863796387 100644
--- a/kiwi/package_manager/pacman.py
+++ b/kiwi/package_manager/pacman.py
@@ -22,7 +22,7 @@
 )
 
 # project
-from kiwi.command import command_call_type
+from kiwi.command import CommandCallT
 from kiwi.command import Command
 from kiwi.package_manager.base import PackageManagerBase
 from kiwi.system.root_bind import RootBind
@@ -110,7 +110,7 @@ def setup_repository_modules(
 
     def process_install_requests_bootstrap(
         self, root_bind: RootBind = None, bootstrap_package: str = None
-    ) -> command_call_type:
+    ) -> CommandCallT:
         """
         Process package install requests for bootstrap phase (no chroot)
 
@@ -139,7 +139,7 @@ def process_install_requests_bootstrap(
             pacman_command, self.command_env
         )
 
-    def process_install_requests(self) -> command_call_type:
+    def process_install_requests(self) -> CommandCallT:
         """
         Process package install requests for image phase (chroot)
 
@@ -158,7 +158,7 @@ def process_install_requests(self) -> command_call_type:
             pacman_command, self.command_env
         )
 
-    def process_delete_requests(self, force: bool = False) -> command_call_type:
+    def process_delete_requests(self, force: bool = False) -> CommandCallT:
         """
         Process package delete requests (chroot)
 
@@ -195,7 +195,7 @@ def process_delete_requests(self, force: bool = False) -> command_call_type:
             self.command_env
         )
 
-    def update(self) -> command_call_type:
+    def update(self) -> CommandCallT:
         """
         Process package update requests (chroot)
 
diff --git a/kiwi/package_manager/zypper.py b/kiwi/package_manager/zypper.py
index 865c282903a..2f71ec7b66c 100644
--- a/kiwi/package_manager/zypper.py
+++ b/kiwi/package_manager/zypper.py
@@ -23,7 +23,7 @@
 
 
 # project
-from kiwi.command import command_call_type
+from kiwi.command import CommandCallT
 from kiwi.command import Command
 from kiwi.package_manager.base import PackageManagerBase
 from kiwi.system.root_bind import RootBind
@@ -114,7 +114,7 @@ def setup_repository_modules(
 
     def process_install_requests_bootstrap(
         self, root_bind: RootBind = None, bootstrap_package: str = None
-    ) -> command_call_type:
+    ) -> CommandCallT:
         """
         Process package install requests for bootstrap phase (no chroot)
 
@@ -134,7 +134,7 @@ def process_install_requests_bootstrap(
             command, self.command_env
         )
 
-    def process_install_requests(self) -> command_call_type:
+    def process_install_requests(self) -> CommandCallT:
         """
         Process package install requests for image phase (chroot)
 
@@ -165,7 +165,7 @@ def process_install_requests(self) -> command_call_type:
             self.chroot_command_env
         )
 
-    def process_delete_requests(self, force: bool = False) -> command_call_type:
+    def process_delete_requests(self, force: bool = False) -> CommandCallT:
         """
         Process package delete requests (chroot)
 
@@ -211,7 +211,7 @@ def process_delete_requests(self, force: bool = False) -> command_call_type:
                 zypper_command, self.chroot_command_env
             )
 
-    def update(self) -> command_call_type:
+    def update(self) -> CommandCallT:
         """
         Process package update requests (chroot)
 
diff --git a/kiwi/partitioner/msdos.py b/kiwi/partitioner/msdos.py
index fb105e6d749..55ab202769d 100644
--- a/kiwi/partitioner/msdos.py
+++ b/kiwi/partitioner/msdos.py
@@ -91,7 +91,8 @@ def set_flag(self, partition_id: int, flag_name: str) -> None:
             raise KiwiPartitionerMsDosFlagError(
                 'Unknown partition flag %s' % flag_name
             )
-        if self.flag_map[flag_name]:
+        flag_val = self.flag_map[flag_name]
+        if flag_val:
             if flag_name == 'f.active':
                 Command.run(
                     [
@@ -100,10 +101,11 @@ def set_flag(self, partition_id: int, flag_name: str) -> None:
                     ]
                 )
             else:
+                assert isinstance(flag_val, str), f"flag {flag_name} must be a string but got a {type(flag_val)}"
                 Command.run(
                     [
                         'sfdisk', '-c', self.disk_device,
-                        format(partition_id), self.flag_map[flag_name]
+                        format(partition_id), flag_val
                     ]
                 )
         else:
diff --git a/kiwi/path.py b/kiwi/path.py
index 35fe9dd99a9..787426c0464 100644
--- a/kiwi/path.py
+++ b/kiwi/path.py
@@ -18,7 +18,7 @@
 import os
 import logging
 import collections
-from typing import Dict, List, Optional
+from typing import Dict, List, MutableMapping, Optional
 
 # project
 from kiwi.command import Command
@@ -224,7 +224,7 @@ def rebase_to_root(root: str, elements: List[str]) -> List[str]:
     @staticmethod
     def which(
         filename: str, alternative_lookup_paths: Optional[List[str]] = None,
-        custom_env: Optional[Dict[str, str]] = None,
+        custom_env: Optional[MutableMapping[str, str]] = None,
         access_mode: Optional[int] = None,
         root_dir: Optional[str] = None
     ) -> Optional[str]:
diff --git a/kiwi/storage/raid_device.py b/kiwi/storage/raid_device.py
index 58394079241..21f35aa1a10 100644
--- a/kiwi/storage/raid_device.py
+++ b/kiwi/storage/raid_device.py
@@ -108,6 +108,8 @@ def create_raid_config(self, filename: str) -> None:
 
         :param string filename: config file name
         """
+        if not self.raid_device:
+            raise KiwiRaidSetupError("No raid device defined, cannot create raid config!")
         mdadm_call = Command.run(
             ['mdadm', '-Db', self.raid_device]
         )
diff --git a/kiwi/system/setup.py b/kiwi/system/setup.py
index e9f780f88a5..706f4bdc9b4 100644
--- a/kiwi/system/setup.py
+++ b/kiwi/system/setup.py
@@ -23,7 +23,7 @@
 from collections import OrderedDict
 from collections import namedtuple
 from typing import (
-    Any, List
+    Any, List, Optional
 )
 
 # project
@@ -1154,7 +1154,7 @@ def _call_script(
             self.setup_selinux_file_contexts()
 
     def _call_script_no_chroot(
-        self, name, option_list, working_directory
+        self, name: str, option_list: List[str], working_directory: Optional[str]
     ):
         if not working_directory:
             working_directory = self.root_dir
diff --git a/kiwi/tasks/result_bundle.py b/kiwi/tasks/result_bundle.py
index 7aa7cb157ef..ca1eec43246 100644
--- a/kiwi/tasks/result_bundle.py
+++ b/kiwi/tasks/result_bundle.py
@@ -196,8 +196,7 @@ def process(self):
                 if result_file.compress:
                     log.info('--> XZ compressing')
                     compress = Compress(bundle_file)
-                    compress.xz(self.runtime_config.get_xz_options())
-                    bundle_file = compress.compressed_filename
+                    bundle_file = compress.xz(self.runtime_config.get_xz_options())
 
                 if self.command_args['--zsync-source'] and result_file.shasum:
                     # Files with a checksum are considered to be image files
diff --git a/kiwi/utils/command_capabilities.py b/kiwi/utils/command_capabilities.py
index e009aefbc70..d9df2054f2c 100644
--- a/kiwi/utils/command_capabilities.py
+++ b/kiwi/utils/command_capabilities.py
@@ -78,7 +78,7 @@ def has_option_in_help(
     def check_version(
         call, version_waterline, version_flags=None,
         root=None, raise_on_error=True
-    ):
+    ) -> bool:
         """
         Checks if the given command version is equal or higher than
         the given version tuple.
diff --git a/test/unit/builder/install_test.py b/test/unit/builder/install_test.py
index 1d66a8b937a..a4351de4099 100644
--- a/test/unit/builder/install_test.py
+++ b/test/unit/builder/install_test.py
@@ -342,6 +342,8 @@ def test_create_install_pxe_archive(
         mock_md5.return_value = checksum
 
         compress = mock.Mock()
+        src = 'target_dir/result-image.x86_64-1.2.3.raw'
+        compress.xz.return_value = src
         mock_compress.return_value = compress
 
         m_open = mock_open()
@@ -349,15 +351,11 @@ def test_create_install_pxe_archive(
             self.install_image.create_install_pxe_archive()
 
         mock_compress.assert_called_once_with(
-            keep_source_on_compress=True,
-            source_filename='target_dir/result-image.x86_64-1.2.3.raw'
+            keep_source_on_compress=True, source_filename=src
         )
         compress.xz.assert_called_once_with(None)
         assert mock_command.call_args_list[0] == call(
-            [
-                'mv', compress.compressed_filename,
-                'tmpdir/result-image.x86_64-1.2.3.xz'
-            ]
+            ['mv', src, 'tmpdir/result-image.x86_64-1.2.3.xz']
         )
         mock_md5.assert_called_once_with(
             'target_dir/result-image.x86_64-1.2.3.raw'
diff --git a/test/unit/command_test.py b/test/unit/command_test.py
index 5b485c164d7..8e83899e6cb 100644
--- a/test/unit/command_test.py
+++ b/test/unit/command_test.py
@@ -4,6 +4,8 @@
 import unittest.mock as mock
 import os
 
+import pytest
+
 from kiwi.command import Command
 
 from kiwi.exceptions import (
@@ -30,7 +32,7 @@ def test_run_raises_error(self, mock_popen, mock_which):
     @patch('subprocess.Popen')
     def test_run_failure(self, mock_popen, mock_which):
         mock_which.return_value = 'command'
-        mock_popen.side_effect = KiwiCommandError('Run failure')
+        mock_popen.side_effect = OSError('Run failure')
         with raises(KiwiCommandError):
             Command.run(['command', 'args'])
 
@@ -55,10 +57,33 @@ def test_run_does_not_raise_error(self, mock_popen, mock_which):
     @patch('kiwi.path.Path.which')
     def test_run_does_not_raise_error_if_command_not_found(self, mock_which):
         mock_which.return_value = None
-        result = Command.run(['command', 'args'], os.environ, False)
-        assert result.error is None
-        assert result.output is None
-        assert result.returncode == -1
+        result = Command.run(['command', 'args'], os.environ, raise_on_command_not_found=False)
+        assert result is None
+
+    @patch('kiwi.path.Path.which')
+    @patch('os.path.exists')
+    @patch('subprocess.Popen')
+    def test_run_does_not_call_which_for_abspaths(self, mock_popen, mock_exists, mock_which):
+        mock_exists.return_value = True
+        proc = mock.MagicMock()
+        proc.communicate.return_value = (str.encode("stdout"), str.encode("stderr"))
+        proc.returncode = 0
+        mock_popen.return_value = proc
+
+        result = Command.run(['/bin/command', 'args'])
+        mock_which.assert_not_called()
+        assert result is not None
+
+    @patch('kiwi.path.Path.which')
+    @patch('os.path.exists')
+    def test_run_fails_for_non_existent_abspath(self, mock_exists, mock_which):
+        mock_exists.return_value = False
+
+        with pytest.raises(KiwiCommandNotFound) as cmd_not_found_err:
+            Command.run(['/bin/command', 'args'])
+
+        mock_which.assert_not_called()
+        assert '"/bin/command" not found' in str(cmd_not_found_err.value)
 
     @patch('os.access')
     @patch('os.path.exists')
@@ -90,17 +115,18 @@ def test_call_command_does_not_exist(self):
         with raises(KiwiCommandNotFound):
             Command.call(['does-not-exist'], os.environ)
 
+    @pytest.mark.parametrize("available", (True, False))
     @patch('kiwi.path.Path.which')
     @patch('subprocess.Popen')
     @patch('select.select')
-    def test_call(self, mock_select, mock_popen, mock_which):
+    def test_call(self, mock_select, mock_popen, mock_which, available: bool):
         mock_which.return_value = 'command'
-        mock_select.return_value = [True, False, False]
+        mock_select.return_value = [True, False, not available]
         mock_process = mock.Mock()
         mock_popen.return_value = mock_process
         call = Command.call(['command', 'args'])
-        assert call.output_available()
-        assert call.error_available()
+        assert call.output_available() == available
+        assert call.error_available() == available
         assert call.output == mock_process.stdout
         assert call.error == mock_process.stderr
         assert call.process == mock_process
diff --git a/test/unit/path_test.py b/test/unit/path_test.py
index dbd04bddb3b..eebdef002bd 100644
--- a/test/unit/path_test.py
+++ b/test/unit/path_test.py
@@ -108,7 +108,7 @@ def test_which(self, mock_exists, mock_env, mock_access):
         assert Path.which('some-file') is None
         mock_env.return_value = None
         mock_exists.return_value = True
-        assert Path.which('some-file', ['alternative']) == \
+        assert Path.which('some-file', alternative_lookup_paths=['alternative']) == \
             'alternative/some-file'
         mock_access.return_value = False
         mock_env.return_value = '/usr/local/bin:/usr/bin:/bin'
@@ -134,7 +134,6 @@ def test_which_not_found_log(
         mock_exists.return_value = False
         with self._caplog.at_level(logging.DEBUG):
             assert Path.which('file') is None
-            print(self._caplog.text)
             assert (
                 '"file": in paths "{0}" exists: "False" mode match: '
                 'not checked'
diff --git a/test/unit/shell_test.py b/test/unit/shell_test.py
index 983afe0fe51..8b6204d4426 100644
--- a/test/unit/shell_test.py
+++ b/test/unit/shell_test.py
@@ -11,7 +11,7 @@ def test_quote(self):
 
     @patch('kiwi.path.Path.which')
     def test_quote_key_value_file(self, mock_which):
-        mock_which.return_value = 'cp'
+        mock_which.side_effect = ['cp', 'bash']
         assert Shell.quote_key_value_file('../data/key_value') == [
             "foo='bar'",
             "bar='xxx'",
diff --git a/test/unit/storage/raid_device_test.py b/test/unit/storage/raid_device_test.py
index af7f2fea257..70828dc11ee 100644
--- a/test/unit/storage/raid_device_test.py
+++ b/test/unit/storage/raid_device_test.py
@@ -80,6 +80,16 @@ def test_create_raid_config(self, mock_command):
         m_open.return_value.write.assert_called_once_with('data')
         self.raid.raid_device = None
 
+    @patch('kiwi.storage.raid_device.Command.run')
+    def test_create_raid_config_without_raid_device(self, mock_command):
+        self.raid.raid_device = None
+
+        with raises(KiwiRaidSetupError) as raid_err_ctx:
+            self.raid.create_raid_config('mdadm.conf')
+
+        assert "No raid device" in str(raid_err_ctx.value)
+        mock_command.assert_not_called()
+
     def test_is_loop(self):
         assert self.raid.is_loop() is True
 
diff --git a/test/unit/system/profile_test.py b/test/unit/system/profile_test.py
index b7f9a0d16e9..a8736b18f58 100644
--- a/test/unit/system/profile_test.py
+++ b/test/unit/system/profile_test.py
@@ -27,7 +27,7 @@ def setup_method(self, cls):
 
     @patch('kiwi.path.Path.which')
     def test_create_live(self, mock_which):
-        mock_which.return_value = 'cp'
+        mock_which.side_effect = ['cp', 'bash']
         self.live_profile.create(self.profile_file)
         os.remove(self.profile_file)
         assert self.live_profile.dot_profile == {
@@ -76,7 +76,7 @@ def test_create_live(self, mock_which):
 
     @patch('kiwi.path.Path.which')
     def test_create_oem(self, mock_which):
-        mock_which.return_value = 'cp'
+        mock_which.side_effect = ['cp', 'bash']
         self.profile.create(self.profile_file)
         os.remove(self.profile_file)
         assert self.profile.dot_profile == {
@@ -159,7 +159,7 @@ def test_create_oem(self, mock_which):
 
     @patch('kiwi.path.Path.which')
     def test_create_displayname_is_image_name(self, mock_which):
-        mock_which.return_value = 'cp'
+        mock_which.side_effect = ['cp', 'bash']
         description = XMLDescription('../data/example_pxe_config.xml')
         profile = Profile(
             XMLState(description.load())
@@ -171,7 +171,7 @@ def test_create_displayname_is_image_name(self, mock_which):
 
     @patch('kiwi.path.Path.which')
     def test_create_cpio(self, mock_which):
-        mock_which.return_value = 'cp'
+        mock_which.side_effect = ['cp', 'bash']
         description = XMLDescription('../data/example_dot_profile_config.xml')
         profile = Profile(
             XMLState(description.load(), None, 'cpio')
diff --git a/test/unit/tasks/result_bundle_test.py b/test/unit/tasks/result_bundle_test.py
index 7bb2f6caba0..3174134dc5b 100644
--- a/test/unit/tasks/result_bundle_test.py
+++ b/test/unit/tasks/result_bundle_test.py
@@ -102,7 +102,7 @@ def test_process_result_bundle(
         checksum = Mock()
         compress = Mock()
         mock_path_which.return_value = 'zsyncmake'
-        compress.compressed_filename = 'compressed_filename'
+        compress.xz.return_value = 'compressed_filename'
         mock_compress.return_value = compress
         mock_checksum.return_value = checksum
         mock_exists.return_value = False
@@ -139,7 +139,7 @@ def test_process_result_bundle(
             os.sep.join([self.abs_bundle_dir, 'test-image-1.2.3-Build_42'])
         )
         mock_checksum.assert_called_once_with(
-            compress.compressed_filename
+            'compressed_filename'
         )
         checksum.sha256.assert_called_once_with()
         m_open.return_value.write.assert_called_once_with(
@@ -168,7 +168,7 @@ def test_process_result_bundle_as_rpm(
         checksum = Mock()
         compress = Mock()
         mock_path_which.return_value = 'zsyncmake'
-        compress.compressed_filename = 'compressed_filename'
+        compress.xz.return_value = 'compressed_filename'
         mock_compress.return_value = compress
         mock_checksum.return_value = checksum
         mock_exists.return_value = False
@@ -303,7 +303,7 @@ def test_process_result_bundle_zsyncmake_missing(
         checksum = Mock()
         compress = Mock()
         mock_path_which.return_value = None
-        compress.compressed_filename = 'compressed_filename'
+        compress.xz.return_value = 'compressed_filename'
         mock_compress.return_value = compress
         mock_checksum.return_value = checksum
         mock_exists.return_value = False
diff --git a/test/unit/utils/compress_test.py b/test/unit/utils/compress_test.py
index 199e87c52eb..a5f2dabc3ce 100644
--- a/test/unit/utils/compress_test.py
+++ b/test/unit/utils/compress_test.py
@@ -95,9 +95,11 @@ def test_uncompress_unknown_format(self, mock_format):
 
     @patch('kiwi.path.Path.which')
     def test_get_format(self, mock_which):
-        mock_which.return_value = 'ziptool'
+        mock_which.side_effect = ['xz']
         xz = Compress('../data/xz_data.xz')
         assert xz.get_format() == 'xz'
+
+        mock_which.side_effect = ['xz', 'gzip']
         gzip = Compress('../data/gz_data.gz')
         assert gzip.get_format() == 'gzip'
 
diff --git a/tox.ini b/tox.ini
index 3fbd704b7cd..55865535eee 100644
--- a/tox.ini
+++ b/tox.ini
@@ -21,12 +21,14 @@ envlist =
     unit_py3_11,
     unit_py3_10,
     unit_py3_9,
+    unit_py3_8,
+    unit_py3_7,
     packagedoc
 
 
 [testenv]
 description =
-    {unit_py3_9,unit_py3_10,unit_py3_11,unit_py3_12}: Unit Test run with basepython set to {basepython}
+    {unit_py3_7,unit_py3_8,unit_py3_9,unit_py3_10,unit_py3_11,unit_py3_12}: Unit Test run with basepython set to {basepython}
     devel: Test KIWI
 allowlist_externals =
     bash
@@ -44,6 +46,8 @@ basepython =
     unit_py3_11: python3.11
     unit_py3_10: python3.10
     unit_py3_9: python3.9
+    unit_py3_8: python3.8
+    unit_py3_7: python3.7
     release: python3.10
     check: python3
     devel: python3
@@ -55,42 +59,80 @@ deps =
     -r.virtualenv.dev-requirements.txt
 
 
-# Unit Test run with basepython set to 3.9
+# Test run with basepython set to 3.7
+# Only static type checking is performed for 3.7
+# because the unit test code base requires python >= 3.8
+[testenv:unit_py3_7]
+setenv =
+    PYTHONPATH={toxinidir}/test
+changedir=test/unit
+commands =
+    {[testenv:mypy]commands}
+
+# Test run with basepython set to 3.8
+[testenv:unit_py3_8]
+setenv =
+    PYTHONPATH={toxinidir}/test
+changedir=test/unit
+commands =
+    {[testenv:mypy]commands}
+    {[testenv:unit]commands}
+
+# Test run with basepython set to 3.9
 [testenv:unit_py3_9]
 setenv =
     PYTHONPATH={toxinidir}/test
 changedir=test/unit
 commands =
+    {[testenv:mypy]commands}
     {[testenv:unit]commands}
 
 
-# Unit Test run with basepython set to 3.10
+# Test run with basepython set to 3.10
 [testenv:unit_py3_10]
 setenv =
     PYTHONPATH={toxinidir}/test
 changedir=test/unit
 commands =
+    {[testenv:mypy]commands}
     {[testenv:unit]commands}
 
 
-# Unit Test run with basepython set to 3.11
+# Test run with basepython set to 3.11
 [testenv:unit_py3_11]
 setenv =
     PYTHONPATH={toxinidir}/test
 changedir=test/unit
 commands =
+    {[testenv:mypy]commands}
     {[testenv:unit]commands}
 
 
-# Unit Test run with basepython set to 3.12
+# Test run with basepython set to 3.12
 [testenv:unit_py3_12]
 setenv =
     PYTHONPATH={toxinidir}/test
 changedir=test/unit
 commands =
+    {[testenv:mypy]commands}
     {[testenv:unit]commands}
 
 
+[testenv:mypy]
+description = Static Type Checking Base
+skip_install = True
+usedevelop = True
+setenv =
+    PYTHONUNBUFFERED=yes
+    WITH_COVERAGE=yes
+passenv =
+    *
+deps = {[testenv]deps}
+changedir=test/unit
+commands =
+    bash -c 'cd ../../ && mypy kiwi'
+
+
 [testenv:unit]
 description = Unit Test Base
 skip_install = True