diff --git a/commands/apt.go b/commands/apt.go
index 70c14a4..e9c6845 100644
--- a/commands/apt.go
+++ b/commands/apt.go
@@ -39,7 +39,7 @@ const (
 
 	// Environment variable for disabling interactive prompts in frontends of
 	// commands like apt-get
-	frontendNoninteractive = "DEBIAN_FRONTEND=noninteractive"
+	EnvFrontendNoninteractive = "DEBIAN_FRONTEND=noninteractive"
 
 	// the basic format for specifying a proxy option for apt:
 	aptProxySettingFormat = "Acquire::%s::Proxy %q;"
@@ -50,12 +50,12 @@ const (
 
 // aptCmder is the packageCommander instantiation for apt-based systems.
 var aptCmder = packageCommander{
-	prereq:                buildCommand(frontendNoninteractive, aptget, "install python-software-properties"),
-	update:                buildCommand(frontendNoninteractive, aptget, "update"),
-	upgrade:               buildCommand(frontendNoninteractive, aptget, "upgrade"),
-	install:               buildCommand(frontendNoninteractive, aptget, "install"),
-	remove:                buildCommand(frontendNoninteractive, aptget, "remove"),
-	purge:                 buildCommand(frontendNoninteractive, aptget, "purge"),
+	prereq:                buildCommand(aptget, "install python-software-properties"),
+	update:                buildCommand(aptget, "update"),
+	upgrade:               buildCommand(aptget, "upgrade"),
+	install:               buildCommand(aptget, "install"),
+	remove:                buildCommand(aptget, "remove"),
+	purge:                 buildCommand(aptget, "purge"),
 	search:                buildCommand(aptcache, "search --names-only ^%s$"),
 	isInstalled:           buildCommand(dpkgquery, "-s %s"),
 	listAvailable:         buildCommand(aptcache, "pkgnames"),
@@ -63,7 +63,7 @@ var aptCmder = packageCommander{
 	addRepository:         buildCommand(addaptrepo, "%q"),
 	listRepositories:      buildCommand(`sed -r -n "s|^deb(-src)? (.*)|\2|p"`, "/etc/apt/sources.list"),
 	removeRepository:      buildCommand(addaptrepo, "--remove ppa:%s"),
-	cleanup:               buildCommand(frontendNoninteractive, aptget, "autoremove"),
+	cleanup:               buildCommand(aptget, "autoremove"),
 	getProxy:              buildCommand(aptconfig, "Acquire::http::Proxy Acquire::https::Proxy Acquire::ftp::Proxy"),
 	proxySettingsFormat:   aptProxySettingFormat,
 	setProxy:              buildCommand("echo %s >> ", AptConfFilePath),
diff --git a/manager/apt.go b/manager/apt.go
index 12a3387..0725f19 100644
--- a/manager/apt.go
+++ b/manager/apt.go
@@ -48,7 +48,7 @@ func NewAptPackageManager() PackageManager {
 
 // Search is defined on the PackageManager interface.
 func (apt *apt) Search(pack string) (bool, error) {
-	out, _, err := RunCommandWithRetry(apt.cmder.SearchCmd(pack), apt, apt.retryPolicy)
+	out, _, err := RunCommandWithRetry(apt.cmder.SearchCmd(pack), apt, apt.retryPolicy, nil)
 	if err != nil {
 		return false, err
 	}
@@ -63,7 +63,7 @@ func (apt *apt) Search(pack string) (bool, error) {
 
 // Install is defined on the PackageManager interface.
 func (apt *apt) Install(packs ...string) error {
-	_, _, err := RunCommandWithRetry(apt.cmder.InstallCmd(packs...), apt.installRetryable, apt.retryPolicy)
+	_, _, err := RunCommandWithRetry(apt.cmder.InstallCmd(packs...), apt.installRetryable, apt.retryPolicy, []string{commands.EnvFrontendNoninteractive})
 	return err
 }
 
diff --git a/manager/manager.go b/manager/manager.go
index 3cfec59..139913d 100644
--- a/manager/manager.go
+++ b/manager/manager.go
@@ -23,37 +23,37 @@ type basePackageManager struct {
 
 // InstallPrerequisite is defined on the PackageManager interface.
 func (pm *basePackageManager) InstallPrerequisite() error {
-	_, _, err := RunCommandWithRetry(pm.cmder.InstallPrerequisiteCmd(), pm, pm.retryPolicy)
+	_, _, err := RunCommandWithRetry(pm.cmder.InstallPrerequisiteCmd(), pm, pm.retryPolicy, nil)
 	return err
 }
 
 // Update is defined on the PackageManager interface.
 func (pm *basePackageManager) Update() error {
-	_, _, err := RunCommandWithRetry(pm.cmder.UpdateCmd(), pm, pm.retryPolicy)
+	_, _, err := RunCommandWithRetry(pm.cmder.UpdateCmd(), pm, pm.retryPolicy, nil)
 	return err
 }
 
 // Upgrade is defined on the PackageManager interface.
 func (pm *basePackageManager) Upgrade() error {
-	_, _, err := RunCommandWithRetry(pm.cmder.UpgradeCmd(), pm, pm.retryPolicy)
+	_, _, err := RunCommandWithRetry(pm.cmder.UpgradeCmd(), pm, pm.retryPolicy, nil)
 	return err
 }
 
 // Install is defined on the PackageManager interface.
 func (pm *basePackageManager) Install(packs ...string) error {
-	_, _, err := RunCommandWithRetry(pm.cmder.InstallCmd(packs...), pm, pm.retryPolicy)
+	_, _, err := RunCommandWithRetry(pm.cmder.InstallCmd(packs...), pm, pm.retryPolicy, nil)
 	return err
 }
 
 // Remove is defined on the PackageManager interface.
 func (pm *basePackageManager) Remove(packs ...string) error {
-	_, _, err := RunCommandWithRetry(pm.cmder.RemoveCmd(packs...), pm, pm.retryPolicy)
+	_, _, err := RunCommandWithRetry(pm.cmder.RemoveCmd(packs...), pm, pm.retryPolicy, nil)
 	return err
 }
 
 // Purge is defined on the PackageManager interface.
 func (pm *basePackageManager) Purge(packs ...string) error {
-	_, _, err := RunCommandWithRetry(pm.cmder.PurgeCmd(packs...), pm, pm.retryPolicy)
+	_, _, err := RunCommandWithRetry(pm.cmder.PurgeCmd(packs...), pm, pm.retryPolicy, nil)
 	return err
 }
 
@@ -67,19 +67,19 @@ func (pm *basePackageManager) IsInstalled(pack string) bool {
 
 // AddRepository is defined on the PackageManager interface.
 func (pm *basePackageManager) AddRepository(repo string) error {
-	_, _, err := RunCommandWithRetry(pm.cmder.AddRepositoryCmd(repo), pm, pm.retryPolicy)
+	_, _, err := RunCommandWithRetry(pm.cmder.AddRepositoryCmd(repo), pm, pm.retryPolicy, nil)
 	return err
 }
 
 // RemoveRepository is defined on the PackageManager interface.
 func (pm *basePackageManager) RemoveRepository(repo string) error {
-	_, _, err := RunCommandWithRetry(pm.cmder.RemoveRepositoryCmd(repo), pm, pm.retryPolicy)
+	_, _, err := RunCommandWithRetry(pm.cmder.RemoveRepositoryCmd(repo), pm, pm.retryPolicy, nil)
 	return err
 }
 
 // Cleanup is defined on the PackageManager interface.
 func (pm *basePackageManager) Cleanup() error {
-	_, _, err := RunCommandWithRetry(pm.cmder.CleanupCmd(), pm, pm.retryPolicy)
+	_, _, err := RunCommandWithRetry(pm.cmder.CleanupCmd(), pm, pm.retryPolicy, nil)
 	return err
 }
 
diff --git a/manager/manager_test.go b/manager/manager_test.go
index 513b822..36dbcbd 100644
--- a/manager/manager_test.go
+++ b/manager/manager_test.go
@@ -82,8 +82,8 @@ var (
 // getMockRunCommandWithRetry returns a function with the same signature as
 // RunCommandWithRetry which saves the command it receives in the provided
 // string whilst always returning no output, 0 error code and nil error.
-func getMockRunCommandWithRetry(stor *string) func(string, manager.Retryable, manager.RetryPolicy) (string, int, error) {
-	return func(cmd string, _ manager.Retryable, _ manager.RetryPolicy) (string, int, error) {
+func getMockRunCommandWithRetry(stor *string) func(string, manager.Retryable, manager.RetryPolicy, []string) (string, int, error) {
+	return func(cmd string, _ manager.Retryable, _ manager.RetryPolicy, _ []string) (string, int, error) {
 		*stor = cmd
 		return "", 0, nil
 	}
diff --git a/manager/run.go b/manager/run.go
index 2123edb..a5bd2eb 100644
--- a/manager/run.go
+++ b/manager/run.go
@@ -78,7 +78,7 @@ func DefaultRetryPolicy() RetryPolicy {
 // It returns the output of the command, the exit code, and an error, if one occurs,
 // logging along the way.
 // It was aliased for testing purposes.
-var RunCommandWithRetry = func(cmd string, retryable Retryable, policy RetryPolicy) (output string, code int, _ error) {
+var RunCommandWithRetry = func(cmd string, retryable Retryable, policy RetryPolicy, envVariables []string) (output string, code int, _ error) {
 	// split the command for use with exec
 	args := strings.Fields(cmd)
 	if len(args) <= 1 {
@@ -105,6 +105,7 @@ var RunCommandWithRetry = func(cmd string, retryable Retryable, policy RetryPoli
 			// Create the command for each attempt, because we need to
 			// call cmd.CombinedOutput only once. See http://pad.lv/1394524.
 			command := exec.Command(args[0], args[1:]...)
+			command.Env = append(os.Environ(), envVariables...)
 
 			var err error
 			out, err = CommandOutput(command)
diff --git a/manager/snap.go b/manager/snap.go
index b63a1cc..f4e1c00 100644
--- a/manager/snap.go
+++ b/manager/snap.go
@@ -65,7 +65,7 @@ func NewSnapPackageManager() *Snap {
 
 // Search is defined on the PackageManager interface.
 func (snap *Snap) Search(pack string) (bool, error) {
-	out, _, err := RunCommandWithRetry(snap.cmder.SearchCmd(pack), snap, snap.retryPolicy)
+	out, _, err := RunCommandWithRetry(snap.cmder.SearchCmd(pack), snap, snap.retryPolicy, nil)
 	if strings.Contains(combinedOutput(out, err), "error: no snap found") {
 		return false, nil
 	} else if err != nil {
@@ -77,7 +77,7 @@ func (snap *Snap) Search(pack string) (bool, error) {
 
 // IsInstalled is defined on the PackageManager interface.
 func (snap *Snap) IsInstalled(pack string) bool {
-	out, _, err := RunCommandWithRetry(snap.cmder.IsInstalledCmd(pack), snap, snap.retryPolicy)
+	out, _, err := RunCommandWithRetry(snap.cmder.IsInstalledCmd(pack), snap, snap.retryPolicy, nil)
 	if strings.Contains(combinedOutput(out, err), "error: no matching snaps installed") || err != nil {
 		return false
 	}
@@ -86,7 +86,7 @@ func (snap *Snap) IsInstalled(pack string) bool {
 
 // InstalledChannel returns the snap channel for an installed package.
 func (snap *Snap) InstalledChannel(pack string) string {
-	out, _, err := RunCommandWithRetry(fmt.Sprintf("snap info %s", pack), snap, snap.retryPolicy)
+	out, _, err := RunCommandWithRetry(fmt.Sprintf("snap info %s", pack), snap, snap.retryPolicy, nil)
 	combined := combinedOutput(out, err)
 	matches := trackingRE.FindAllStringSubmatch(combined, 1)
 	if len(matches) == 0 {
@@ -99,7 +99,7 @@ func (snap *Snap) InstalledChannel(pack string) string {
 // ChangeChannel updates the tracked channel for an installed snap.
 func (snap *Snap) ChangeChannel(pack, channel string) error {
 	cmd := fmt.Sprintf("snap refresh --channel %s %s", channel, pack)
-	out, _, err := RunCommandWithRetry(cmd, snap, snap.retryPolicy)
+	out, _, err := RunCommandWithRetry(cmd, snap, snap.retryPolicy, nil)
 	if err != nil {
 		return err
 	} else if strings.Contains(combinedOutput(out, err), "not installed") {
@@ -111,7 +111,7 @@ func (snap *Snap) ChangeChannel(pack, channel string) error {
 
 // Install is defined on the PackageManager interface.
 func (snap *Snap) Install(packs ...string) error {
-	out, _, err := RunCommandWithRetry(snap.cmder.InstallCmd(packs...), snap.installRetryable, snap.retryPolicy)
+	out, _, err := RunCommandWithRetry(snap.cmder.InstallCmd(packs...), snap.installRetryable, snap.retryPolicy, nil)
 	if snapNotFoundRE.MatchString(combinedOutput(out, err)) {
 		return errors.New("unable to locate package")
 	}
@@ -122,7 +122,7 @@ func (snap *Snap) Install(packs ...string) error {
 func (snap *Snap) GetProxySettings() (proxy.Settings, error) {
 	var res proxy.Settings
 
-	out, _, err := RunCommandWithRetry(snap.cmder.GetProxyCmd(), snap, snap.retryPolicy)
+	out, _, err := RunCommandWithRetry(snap.cmder.GetProxyCmd(), snap, snap.retryPolicy, nil)
 	if strings.Contains(combinedOutput(out, err), `no "proxy" configuration option`) {
 		return res, nil
 	} else if err != nil {
@@ -170,12 +170,12 @@ func (snap *Snap) ConfigureStoreProxy(assertions, storeID string) error {
 	_ = assertFile.Close()
 
 	ackCmd := fmt.Sprintf("snap ack %s", assertFile.Name())
-	if _, _, err = RunCommandWithRetry(ackCmd, snap, snap.retryPolicy); err != nil {
+	if _, _, err = RunCommandWithRetry(ackCmd, snap, snap.retryPolicy, nil); err != nil {
 		return errors.Annotate(err, "failed to execute 'snap ack'")
 	}
 
 	setCmd := fmt.Sprintf("snap set system proxy.store=%s", storeID)
-	if _, _, err = RunCommandWithRetry(setCmd, snap, snap.retryPolicy); err != nil {
+	if _, _, err = RunCommandWithRetry(setCmd, snap, snap.retryPolicy, nil); err != nil {
 		return errors.Annotatef(err, "failed to configure snap to use store ID %q", storeID)
 	}
 
@@ -189,7 +189,7 @@ func (snap *Snap) ConfigureStoreProxy(assertions, storeID string) error {
 // call to SetProxy.
 func (snap *Snap) DisableStoreProxy() error {
 	setCmd := "snap set system proxy.store="
-	if _, _, err := RunCommandWithRetry(setCmd, snap, snap.retryPolicy); err != nil {
+	if _, _, err := RunCommandWithRetry(setCmd, snap, snap.retryPolicy, nil); err != nil {
 		return errors.Annotate(err, "failed to configure snap to not use a store proxy")
 	}
 
diff --git a/manager/yum.go b/manager/yum.go
index d60eab8..0981005 100644
--- a/manager/yum.go
+++ b/manager/yum.go
@@ -37,7 +37,7 @@ func NewYumPackageManager() PackageManager {
 
 // Search is defined on the PackageManager interface.
 func (yum *yum) Search(pack string) (bool, error) {
-	_, code, err := RunCommandWithRetry(yum.cmder.SearchCmd(pack), yum, yum.retryPolicy)
+	_, code, err := RunCommandWithRetry(yum.cmder.SearchCmd(pack), yum, yum.retryPolicy, nil)
 
 	// yum list package returns 1 when it cannot find the package.
 	if code == 1 {
diff --git a/manager/zypper.go b/manager/zypper.go
index 4053ec0..43a69c2 100644
--- a/manager/zypper.go
+++ b/manager/zypper.go
@@ -36,7 +36,7 @@ func NewZypperPackageManager() PackageManager {
 
 // Search is defined on the PackageManager interface.
 func (zypper *zypper) Search(pack string) (bool, error) {
-	_, code, err := RunCommandWithRetry(zypper.cmder.SearchCmd(pack), zypper, zypper.retryPolicy)
+	_, code, err := RunCommandWithRetry(zypper.cmder.SearchCmd(pack), zypper, zypper.retryPolicy, nil)
 
 	// zypper search returns 104 when it cannot find the package.
 	if code == 104 {