diff --git a/tools/image-info b/tools/image-info
index 376ac53ef..db31fa725 100755
--- a/tools/image-info
+++ b/tools/image-info
@@ -21,7 +21,7 @@ import xml.etree.ElementTree
 import yaml
 
 from collections import OrderedDict
-from typing import Dict
+from typing import Dict, Any, Generator
 
 from osbuild import loop
 
@@ -70,7 +70,7 @@ def loop_open(ctl, image, *, offset=None, size=None):
 
 
 @contextlib.contextmanager
-def convert_image(ctl, image, fmt):
+def convert_image(image, fmt):
     with tempfile.TemporaryDirectory(dir="/var/tmp") as tmp:
         if fmt["type"] != "raw":
             target = os.path.join(tmp, "image.raw")
@@ -135,6 +135,8 @@ def parse_environment_vars(s):
 def parse_unit_files(s, expected_state):
     r = []
     for line in s.split("\n")[1:]:
+        state = ""
+        unit = ""
         try:
             unit, state, *_ = line.split()
         except ValueError:
@@ -146,7 +148,7 @@ def parse_unit_files(s, expected_state):
     return r
 
 
-def subprocess_check_output(argv, parse_fn=None):
+def subprocess_check_output(argv, parse_fn=None) -> Any:
     try:
         output = subprocess.check_output(argv, encoding="utf-8")
     except subprocess.CalledProcessError as e:
@@ -195,7 +197,7 @@ def read_container_images(tree):
     return images
 
 
-def read_image_format(device):
+def read_image_format(device) -> Dict[str, str]:
     """
     Read image format.
 
@@ -318,7 +320,7 @@ def read_partition_table(device):
     return info
 
 
-def read_bootloader_type(device):
+def read_bootloader_type(device) -> str:
     """
     Read bootloader type from the provided device.
 
@@ -416,16 +418,18 @@ def rpm_verify(tree):
 
     changed = {}
     missing = []
-    for line in rpm.stdout:
-        # format description in rpm(8), under `--verify`
-        attrs = line[:9]
-        if attrs == "missing  ":
-            missing.append(line[12:].rstrip())
-        else:
-            changed[line[13:].rstrip()] = attrs
 
-    # ignore return value, because it returns non-zero when it found changes
-    rpm.wait()
+    if rpm.stdout:
+        for line in rpm.stdout:
+            # format description in rpm(8), under `--verify`
+            attrs = line[:9]
+            if attrs == "missing  ":
+                missing.append(line[12:].rstrip())
+            else:
+                changed[line[13:].rstrip()] = attrs
+
+        # ignore return value, because it returns non-zero when it found changes
+        rpm.wait()
 
     return {
         "missing": sorted(missing),
@@ -433,7 +437,7 @@ def rpm_verify(tree):
     }
 
 
-def rpm_not_installed_docs(tree, is_ostree):
+def rpm_not_installed_docs(tree):
     """
     Gathers information on documentation, which is part of RPM packages,
     but was not installed.
@@ -467,7 +471,7 @@ def rpm_not_installed_docs(tree, is_ostree):
     return sorted(not_installed_docs)
 
 
-def rpm_packages(tree, is_ostree):
+def rpm_packages(tree):
     """
     Read NVRs of RPM packages installed on the system.
 
@@ -494,7 +498,7 @@ def rpm_packages(tree, is_ostree):
         cmd += ["--dbpath", "/usr/share/rpm"]
     elif os.path.exists(os.path.join(tree, "var/lib/rpm")):
         cmd += ["--dbpath", "/var/lib/rpm"]
-    output = subprocess_check_output(cmd)
+    subprocess_check_output(cmd)
     pkgs = subprocess_check_output(cmd, str.split)
     return list(sorted(pkgs))
 
@@ -2271,11 +2275,11 @@ def read_resolv_conf(tree):
 
 def append_filesystem(report, tree, *, is_ostree=False):
     if os.path.exists(f"{tree}/etc/os-release"):
-        report["packages"] = rpm_packages(tree, is_ostree)
+        report["packages"] = rpm_packages(tree)
         if not is_ostree:
             report["rpm-verify"] = rpm_verify(tree)
 
-        not_installed_docs = rpm_not_installed_docs(tree, is_ostree)
+        not_installed_docs = rpm_not_installed_docs(tree)
         if not_installed_docs:
             report["rpm_not_installed_docs"] = not_installed_docs
 
@@ -2485,7 +2489,7 @@ def ensure_device_file(path: str, major: int, minor: int):
 
 
 @contextlib.contextmanager
-def discover_lvm(dev) -> Dict:
+def discover_lvm(dev) -> Generator[Dict[str, Any], None, None]:
     # find the volume group name for the device file
     vg_name = volume_group_for_device(dev)
 
@@ -2532,14 +2536,12 @@ def discover_lvm(dev) -> Dict:
             volumes[name] = info
             if name.startswith("root"):
                 volumes.move_to_end(name, last=False)
-        res = {
+        yield {
             "lvm": True,
             "lvm.vg": vg_name,
             "lvm.volumes": volumes
         }
 
-        yield res
-
     finally:
         r = subprocess.run(["vgchange", "-an", vg_name],
                             stdout=subprocess.DEVNULL,
@@ -2621,13 +2623,13 @@ def append_partitions(report, image, loctl):
         append_filesystem(report, root_tree)
 
 
-def analyse_image(image):
+def analyse_image(image) -> Dict[str, Any]:
     loctl = loop.LoopControl()
 
     imgfmt = read_image_format(image)
-    report = {"image-format": imgfmt}
+    report: Dict[str, Any] = {"image-format": imgfmt}
 
-    with convert_image(loctl, image, imgfmt) as target:
+    with convert_image(image, imgfmt) as target:
         size = os.stat(target).st_size
         with loop_open(loctl, target, offset=0, size=size) as device:
             report["bootloader"] = read_bootloader_type(device)
@@ -2650,7 +2652,7 @@ def append_directory(report, tree):
         # Make sure that the tools which analyse the directory in-place
         # can not modify its content (e.g. create additional files).
         # mount_at() always mounts the source as read-only!
-        with mount_at(tree, tree_ro, ["bind"]) as mountpoint:
+        with mount_at(tree, tree_ro, ["bind"]) as _:
             if os.path.lexists(f"{tree}/ostree"):
                 os.makedirs(f"{tree}/etc", exist_ok=True)
                 with mount_at(f"{tree}/usr/etc", f"{tree}/etc", extra=["--bind"]):
@@ -2700,7 +2702,7 @@ def analyse_directory(path):
 
 
 def is_tarball(path):
-    mtype, encoding = mimetypes.guess_type(path)
+    mtype, _ = mimetypes.guess_type(path)
     return mtype == "application/x-tar"