diff --git a/cmd/metis/gate_test.go b/cmd/metis/gate_test.go
index f76d8f7..b75c01e 100644
--- a/cmd/metis/gate_test.go
+++ b/cmd/metis/gate_test.go
@@ -127,16 +127,75 @@ func TestMainAndCommandFatalBranches(t *testing.T) {
 		main()
 	})
 	mustPanic(func() { configCmd(nil) })
+	root := t.TempDir()
+	invPath, _ := writeTestInventory(t, root)
+	mustPanic(func() { configCmd([]string{"--inventory", invPath, "--node", "missing"}) })
 	mustPanic(func() { planCmd([]string{"--inventory", "/nope", "--node", "titan-15"}) })
 	mustPanic(func() { burnCmd([]string{"--inventory", "/nope", "--node", "titan-15", "--device", "/dev/sdz"}) })
 	mustPanic(func() { imageCmd(nil) })
+	mustPanic(func() {
+		imageCmd([]string{"--inventory", invPath, "--node", "titan-15", "--cache", filepath.Join(root, "cache")})
+	})
 	mustPanic(func() { injectCmd(nil) })
+	mustPanic(func() { injectCmd([]string{"--node", "titan-15"}) })
+	mustPanic(func() {
+		injectCmd([]string{"--inventory", invPath, "--node", "missing", "--boot", filepath.Join(root, "boot")})
+	})
 	mustPanic(func() { factsCmd([]string{"--inventory", "/nope", "--snapshots", "/nope"}) })
+	mustPanic(func() {
+		factsCmd([]string{"--inventory", invPath, "--snapshots", filepath.Join(root, "missing-snaps")})
+	})
+	mustPanic(func() { serveCmd([]string{"--bind", ":0"}) })
+	t.Setenv("METIS_INVENTORY_PATH", invPath)
+	t.Setenv("METIS_DATA_DIR", filepath.Join(root, "data"))
+	listenAndServe = func(string, http.Handler) error { return http.ErrServerClosed }
+	t.Cleanup(func() { listenAndServe = httpListenAndServe })
 	mustPanic(func() { serveCmd([]string{"--bind", ":0"}) })
 	mustPanic(func() { remoteBuildCmd([]string{"--node", "n1"}) })
 	mustPanic(func() { remoteFlashCmd([]string{"--node", "n1"}) })
 }
 
+func TestFactsCmdReportsEncodeErrors(t *testing.T) {
+	root := t.TempDir()
+	invPath, _ := writeTestInventory(t, root)
+	snapDir := filepath.Join(root, "snapshots")
+	if err := os.MkdirAll(snapDir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(snapDir, "snap.json"), []byte(`{"hostname":"titan-15","kernel":"6.6.63"}`), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	oldStdout := os.Stdout
+	oldStderr := os.Stderr
+	badStdout, stdoutWriter, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	stderrReader, stderrWriter, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	os.Stdout = badStdout
+	os.Stderr = stderrWriter
+	t.Cleanup(func() {
+		os.Stdout = oldStdout
+		os.Stderr = oldStderr
+		_ = badStdout.Close()
+		_ = stdoutWriter.Close()
+		_ = stderrReader.Close()
+		_ = stderrWriter.Close()
+	})
+
+	factsCmd([]string{"--inventory", invPath, "--snapshots", snapDir})
+	_ = stderrWriter.Close()
+	buf := make([]byte, 1024)
+	n, _ := stderrReader.Read(buf)
+	if !strings.Contains(string(buf[:n]), "encode:") {
+		t.Fatalf("expected encode error on stderr, got %q", string(buf[:n]))
+	}
+}
+
 func TestRemoteCommandHelpers(t *testing.T) {
 	if !hasMountedChildren([]struct {
 		Mountpoint string `json:"mountpoint"`
diff --git a/pkg/inject/coverage_more_test.go b/pkg/inject/coverage_more_test.go
index 1bf45d9..1663e98 100644
--- a/pkg/inject/coverage_more_test.go
+++ b/pkg/inject/coverage_more_test.go
@@ -33,4 +33,13 @@ func TestInjectorWriteBranches(t *testing.T) {
 	if err := inj.Write([]FileSpec{{Path: "x", Content: []byte("x")}}); err == nil {
 		t.Fatal("expected mkdir error")
 	}
+
+	targetDir := filepath.Join(boot, "already-dir")
+	if err := os.MkdirAll(targetDir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	inj = &Injector{BootPath: boot}
+	if err := inj.Write([]FileSpec{{Path: "already-dir", Content: []byte("x"), Mode: 0o644}}); err == nil {
+		t.Fatal("expected write error when target path is a directory")
+	}
 }