Address PR review comments

internal/runners/install/install.go

@@ -114,7 +114,6 @@ func (i *Install) Run(params Params) (rerr error) {
 	var oldCommit *bpModel.Commit
 	var reqs requirements
 	var ts time.Time
-	var override bool
 	{
 		pg = output.StartSpinner(out, locale.T("progress_search"), constants.TerminalAnimationInterval)
 
@@ -134,7 +133,6 @@ func (i *Install) Run(params Params) (rerr error) {
 		if err != nil {
 			return errs.Wrap(err, "Unable to get timestamp from params")
 		}
-		override = params.Timestamp.String() != ""
 
 		// Get languages used in current project
 		languages, err := model.FetchLanguagesForBuildScript(oldCommit.BuildScript())
@@ -155,7 +153,7 @@ func (i *Install) Run(params Params) (rerr error) {
 
 	// Prepare updated buildscript
 	script := oldCommit.BuildScript()
-	if err := prepareBuildScript(script, reqs, ts, override); err != nil {
+	if err := prepareBuildScript(script, reqs, ts); err != nil {
 		return errs.Wrap(err, "Could not prepare build script")
 	}
 
@@ -342,8 +340,8 @@ func (i *Install) renderUserFacing(reqs requirements) {
 	i.prime.Output().Notice("")
 }
 
-func prepareBuildScript(script *buildscript.BuildScript, requirements requirements, ts time.Time, override bool) error {
-	script.SetAtTime(ts, override)
+func prepareBuildScript(script *buildscript.BuildScript, requirements requirements, ts time.Time) error {
+	script.SetAtTime(ts, true)
 	for _, req := range requirements {
 		requirement := types.Requirement{
 			Namespace:          req.Resolved.Namespace,

internal/runners/platforms/add.go

@@ -98,7 +98,7 @@ func (a *Add) Run(params AddRunParams) (rerr error) {
 
 	// Prepare updated buildscript
 	script := oldCommit.BuildScript()
-	script.SetAtTime(ts, false)
+	script.SetAtTime(ts, true)
 	script.AddPlatform(*platform.PlatformID)
 
 	// Update local checkout and source runtime changes

internal/runners/upgrade/upgrade.go

@@ -111,7 +111,7 @@ func (u *Upgrade) Run(params *Params) (rerr error) {
 	if err != nil {
 		return errs.Wrap(err, "Failed to fetch latest timestamp")
 	}
-	bumpedBS.SetAtTime(ts, params.Timestamp.String() != "")
+	bumpedBS.SetAtTime(ts, true)
 
 	// Since our platform is commit based we need to create a commit for the "after" buildplan, even though we may not
 	// end up using it it the user doesn't confirm the upgrade.

pkg/buildscript/buildscript.go

@@ -56,6 +56,9 @@ func (b *BuildScript) AtTime() *time.Time {
 	return b.atTime
 }
 
+// SetAtTime sets the AtTime value, if the buildscript already has an AtTime value
+// and `override=false` then the value passed here will be discarded.
+// Override should in most cases only be true if we are making changes to the buildscript.
 func (b *BuildScript) SetAtTime(t time.Time, override bool) {
 	if b.atTime != nil && !override {
 		return