diff --git a/cmd/vm/cmd_container.go b/cmd/vm/cmd_container.go
index d586a3e..6df316f 100644
--- a/cmd/vm/cmd_container.go
+++ b/cmd/vm/cmd_container.go
@@ -98,8 +98,8 @@ func runContainer(image, name string, detach bool, memory, cpus, sshPort int) er
 		core.Print(nil, "%s %s", successStyle.Render(i18n.Label("started")), c.ID)
 		core.Print(nil, "%s %d", dimStyle.Render(i18n.T("cmd.vm.label.pid")), c.PID)
 		core.Println()
-		core.Println(i18n.T("cmd.vm.hint.view_logs", map[string]any{"ID": c.ID[:8]}))
-		core.Println(i18n.T("cmd.vm.hint.stop", map[string]any{"ID": c.ID[:8]}))
+		core.Println(i18n.T("cmd.vm.hint.view_logs", map[string]any{"ID": shortContainerID(c.ID)}))
+		core.Println(i18n.T("cmd.vm.hint.stop", map[string]any{"ID": shortContainerID(c.ID)}))
 	} else {
 		core.Println()
 		core.Print(nil, "%s %s", dimStyle.Render(i18n.T("cmd.vm.label.container_stopped")), c.ID)
@@ -184,13 +184,23 @@ func listContainers(all bool) error {
 		}
 
 		core.Print(w, "%s\t%s\t%s\t%s\t%s\t%d",
-			c.ID[:8], c.Name, imageName, status, duration, c.PID)
+			shortContainerID(c.ID), c.Name, imageName, status, duration, c.PID)
+	}
+
+	if err := w.Flush(); err != nil {
+		return coreerr.E("listContainers", "flush output", err)
 	}
 
-	_ = w.Flush()
 	return nil
 }
 
+func shortContainerID(id string) string {
+	if len(id) <= 8 {
+		return id
+	}
+	return id[:8]
+}
+
 func formatDuration(d time.Duration) string {
 	if d < time.Minute {
 		return core.Sprintf("%ds", int(d.Seconds()))
@@ -233,7 +243,7 @@ func stopContainer(id string) error {
 		return err
 	}
 
-	core.Print(nil, "%s %s", dimStyle.Render(i18n.T("cmd.vm.stop.stopping")), fullID[:8])
+	core.Print(nil, "%s %s", dimStyle.Render(i18n.T("cmd.vm.stop.stopping")), shortContainerID(fullID))
 
 	ctx := context.Background()
 	if err := manager.Stop(ctx, fullID); err != nil {
diff --git a/cmd/vm/cmd_templates.go b/cmd/vm/cmd_templates.go
index 95cfb69..c4594f4 100644
--- a/cmd/vm/cmd_templates.go
+++ b/cmd/vm/cmd_templates.go
@@ -88,7 +88,9 @@ func listTemplates() error {
 		}
 		core.Print(w, "%s\t%s", repoNameStyle.Render(tmpl.Name), desc)
 	}
-	_ = w.Flush()
+	if err := w.Flush(); err != nil {
+		return coreerr.E("listTemplates", "flush output", err)
+	}
 
 	core.Println()
 	core.Print(nil, "%s %s", i18n.T("cmd.vm.templates.hint.show"), dimStyle.Render("core vm templates show <name>"))
@@ -209,8 +211,8 @@ func RunFromTemplate(templateName string, vars map[string]string, runOpts contai
 		core.Print(nil, "%s %s", successStyle.Render(i18n.T("common.label.started")), c.ID)
 		core.Print(nil, "%s %d", dimStyle.Render(i18n.T("cmd.vm.label.pid")), c.PID)
 		core.Println()
-		core.Println(i18n.T("cmd.vm.hint.view_logs", map[string]any{"ID": c.ID[:8]}))
-		core.Println(i18n.T("cmd.vm.hint.stop", map[string]any{"ID": c.ID[:8]}))
+		core.Println(i18n.T("cmd.vm.hint.view_logs", map[string]any{"ID": shortContainerID(c.ID)}))
+		core.Println(i18n.T("cmd.vm.hint.stop", map[string]any{"ID": shortContainerID(c.ID)}))
 	} else {
 		core.Println()
 		core.Print(nil, "%s %s", dimStyle.Render(i18n.T("cmd.vm.label.container_stopped")), c.ID)
diff --git a/devenv/devops.go b/devenv/devops.go
index fc721c7..2f22f25 100644
--- a/devenv/devops.go
+++ b/devenv/devops.go
@@ -43,7 +43,7 @@ func New(m io.Medium) (*DevOps, error) {
 		return nil, coreerr.E("devops.New", "failed to create image manager", err)
 	}
 
-	mgr, err := container.NewLinuxKitManager(io.Local)
+	mgr, err := container.NewLinuxKitManager(m)
 	if err != nil {
 		return nil, coreerr.E("devops.New", "failed to create container manager", err)
 	}
diff --git a/devenv/images.go b/devenv/images.go
index 375164f..ec50ccf 100644
--- a/devenv/images.go
+++ b/devenv/images.go
@@ -16,7 +16,6 @@ import (
 // ImageManager handles image downloads and updates.
 type ImageManager struct {
 	medium   io.Medium
-	config   *Config
 	manifest *Manifest
 	sources  []sources.ImageSource
 }
@@ -83,7 +82,6 @@ func NewImageManager(m io.Medium, cfg *Config) (*ImageManager, error) {
 
 	return &ImageManager{
 		medium:   m,
-		config:   cfg,
 		manifest: manifest,
 		sources:  srcs,
 	}, nil
diff --git a/devenv/images_test.go b/devenv/images_test.go
index 4f199dc..cd0dceb 100644
--- a/devenv/images_test.go
+++ b/devenv/images_test.go
@@ -240,7 +240,6 @@ func TestImageManager_InstallNoSourceAvailable_Bad(t *testing.T) {
 	// Create manager with empty sources
 	mgr := &ImageManager{
 		medium:   io.Local,
-		config:   DefaultConfig(),
 		manifest: &Manifest{medium: io.Local, Images: make(map[string]ImageInfo), path: coreutil.JoinPath(tmpDir, "manifest.json")},
 		sources:  nil, // no sources
 	}
@@ -301,7 +300,6 @@ func TestImageManager_InstallWithMockSource_Good(t *testing.T) {
 
 	mgr := &ImageManager{
 		medium:   io.Local,
-		config:   DefaultConfig(),
 		manifest: &Manifest{medium: io.Local, Images: make(map[string]ImageInfo), path: coreutil.JoinPath(tmpDir, "manifest.json")},
 		sources:  []sources.ImageSource{mock},
 	}
@@ -330,7 +328,6 @@ func TestImageManager_InstallDownloadError_Bad(t *testing.T) {
 
 	mgr := &ImageManager{
 		medium:   io.Local,
-		config:   DefaultConfig(),
 		manifest: &Manifest{medium: io.Local, Images: make(map[string]ImageInfo), path: coreutil.JoinPath(tmpDir, "manifest.json")},
 		sources:  []sources.ImageSource{mock},
 	}
@@ -351,7 +348,6 @@ func TestImageManager_InstallVersionError_Bad(t *testing.T) {
 
 	mgr := &ImageManager{
 		medium:   io.Local,
-		config:   DefaultConfig(),
 		manifest: &Manifest{medium: io.Local, Images: make(map[string]ImageInfo), path: coreutil.JoinPath(tmpDir, "manifest.json")},
 		sources:  []sources.ImageSource{mock},
 	}
@@ -377,7 +373,6 @@ func TestImageManager_InstallSkipsUnavailableSource_Good(t *testing.T) {
 
 	mgr := &ImageManager{
 		medium:   io.Local,
-		config:   DefaultConfig(),
 		manifest: &Manifest{medium: io.Local, Images: make(map[string]ImageInfo), path: coreutil.JoinPath(tmpDir, "manifest.json")},
 		sources:  []sources.ImageSource{unavailableMock, availableMock},
 	}
@@ -402,7 +397,6 @@ func TestImageManager_CheckUpdateWithMockSource_Good(t *testing.T) {
 
 	mgr := &ImageManager{
 		medium: io.Local,
-		config: DefaultConfig(),
 		manifest: &Manifest{
 			medium: io.Local,
 			Images: map[string]ImageInfo{
@@ -432,7 +426,6 @@ func TestImageManager_CheckUpdateNoUpdate_Good(t *testing.T) {
 
 	mgr := &ImageManager{
 		medium: io.Local,
-		config: DefaultConfig(),
 		manifest: &Manifest{
 			medium: io.Local,
 			Images: map[string]ImageInfo{
@@ -461,7 +454,6 @@ func TestImageManager_CheckUpdateNoSource_Bad(t *testing.T) {
 
 	mgr := &ImageManager{
 		medium: io.Local,
-		config: DefaultConfig(),
 		manifest: &Manifest{
 			medium: io.Local,
 			Images: map[string]ImageInfo{
@@ -489,7 +481,6 @@ func TestImageManager_CheckUpdateVersionError_Bad(t *testing.T) {
 
 	mgr := &ImageManager{
 		medium: io.Local,
-		config: DefaultConfig(),
 		manifest: &Manifest{
 			medium: io.Local,
 			Images: map[string]ImageInfo{
@@ -511,7 +502,6 @@ func TestImageManager_InstallEmptySources_Bad(t *testing.T) {
 
 	mgr := &ImageManager{
 		medium:   io.Local,
-		config:   DefaultConfig(),
 		manifest: &Manifest{medium: io.Local, Images: make(map[string]ImageInfo), path: coreutil.JoinPath(tmpDir, "manifest.json")},
 		sources:  []sources.ImageSource{}, // Empty slice, not nil
 	}
@@ -530,7 +520,6 @@ func TestImageManager_InstallAllUnavailable_Bad(t *testing.T) {
 
 	mgr := &ImageManager{
 		medium:   io.Local,
-		config:   DefaultConfig(),
 		manifest: &Manifest{medium: io.Local, Images: make(map[string]ImageInfo), path: coreutil.JoinPath(tmpDir, "manifest.json")},
 		sources:  []sources.ImageSource{mock1, mock2},
 	}
@@ -549,7 +538,6 @@ func TestImageManager_CheckUpdateFirstSourceUnavailable_Good(t *testing.T) {
 
 	mgr := &ImageManager{
 		medium: io.Local,
-		config: DefaultConfig(),
 		manifest: &Manifest{
 			medium: io.Local,
 			Images: map[string]ImageInfo{
diff --git a/linuxkit.go b/linuxkit.go
index c248df1..b24e40d 100644
--- a/linuxkit.go
+++ b/linuxkit.go
@@ -351,11 +351,13 @@ type followReader struct {
 	ctx    context.Context
 	cancel context.CancelFunc
 	reader *bufio.Reader
-	medium io.Medium
-	path   string
 }
 
 func newFollowReader(ctx context.Context, m io.Medium, path string) (*followReader, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+
 	file, err := m.Open(path)
 	if err != nil {
 		return nil, err
@@ -370,8 +372,6 @@ func newFollowReader(ctx context.Context, m io.Medium, path string) (*followRead
 		ctx:    ctx,
 		cancel: cancel,
 		reader: bufio.NewReader(file),
-		medium: m,
-		path:   path,
 	}, nil
 }
 
diff --git a/state.go b/state.go
index 2d28023..5bb3178 100644
--- a/state.go
+++ b/state.go
@@ -116,6 +116,10 @@ func (s *State) SaveState() error {
 
 // Add adds a container to the state and persists it.
 func (s *State) Add(c *Container) error {
+	if c == nil {
+		return core.E("State.Add", "container cannot be nil", nil)
+	}
+
 	s.mu.Lock()
 	s.Containers[c.ID] = c
 	s.mu.Unlock()
@@ -140,6 +144,10 @@ func (s *State) Get(id string) (*Container, bool) {
 
 // Update updates a container in the state and persists it.
 func (s *State) Update(c *Container) error {
+	if c == nil {
+		return core.E("State.Update", "container cannot be nil", nil)
+	}
+
 	s.mu.Lock()
 	s.Containers[c.ID] = c
 	s.mu.Unlock()