diff --git a/examples/development/go/hello-world/trace.out b/examples/development/go/hello-world/trace.out
new file mode 100644
index 00000000000..508fa304ee2
Binary files /dev/null and b/examples/development/go/hello-world/trace.out differ
diff --git a/internal/impl/devbox.go b/internal/impl/devbox.go
index 7d0089d8e14..a4edbfa3293 100644
--- a/internal/impl/devbox.go
+++ b/internal/impl/devbox.go
@@ -1172,10 +1172,10 @@ func (d *Devbox) parseEnvAndExcludeSpecialCases(currentEnv []string) (map[string
 		if ignoreCurrentEnvVar[key] {
 			continue
 		}
-		// handling special cases to for pure shell
-		// Passing HOME for pure shell to leak through otherwise devbox binary won't work
-		// We also include PATH to find the nix installation. It is cleaned for pure mode below
-		// TERM leaking through is to enable colored text in the pure shell
+		// handling special cases for pure shell
+		// - HOME required for devbox binary to work
+		// - PATH to find the nix installation. It is cleaned for pure mode below.
+		// - TERM to enable colored text in the pure shell
 		if !d.pure || key == "HOME" || key == "PATH" || key == "TERM" {
 			env[key] = val
 		}
diff --git a/internal/impl/envvars.go b/internal/impl/envvars.go
index 488e9ad0508..2013a05ef1c 100644
--- a/internal/impl/envvars.go
+++ b/internal/impl/envvars.go
@@ -69,8 +69,8 @@ func markEnvsAsSetByDevbox(envs ...map[string]string) {
 	}
 }
 
-// IsEnvEnabled checks if the devbox environment is enabled. We use the ogPathKey
-// as a proxy for this. This allows us to differentiate between global and
+// IsEnvEnabled checks if the devbox environment is enabled.
+// This allows us to differentiate between global and
 // individual project shells.
 func (d *Devbox) IsEnvEnabled() bool {
 	fakeEnv := map[string]string{}
diff --git a/internal/impl/packages.go b/internal/impl/packages.go
index 9db082fea7d..2c204d85f83 100644
--- a/internal/impl/packages.go
+++ b/internal/impl/packages.go
@@ -203,14 +203,22 @@ type installMode string
 const (
 	install   installMode = "install"
 	uninstall installMode = "uninstall"
-	ensure    installMode = "ensure"
+	// update is both install new package version and uninstall old package version
+	update installMode = "update"
+	ensure installMode = "ensure"
 )
 
-// ensurePackagesAreInstalled ensures that the nix profile has the packages specified
-// in the config (devbox.json). The `mode` is used for user messaging to explain
-// what operations are happening, because this function may take time to execute.
-// TODO we should rename this to ensureDevboxEnvironmentIsUpToDate since it does
-// much more than ensuring packages are installed.
+// ensurePackagesAreInstalled ensures:
+//  1. Packages are installed, in nix-profile or runx.
+//     Extraneous packages are removed (references purged, not uninstalled).
+//  2. Files for devbox shellenv are generated
+//  3. Env-vars for shellenv are computed
+//  4. Lockfile is synced
+//
+// The `mode` is used for:
+// 1. Skipping certain operations that may not apply.
+// 2. User messaging to explain what operations are happening, because this function may take time to execute.
+// TODO: Rename method since it does more than just ensure packages are installed.
 func (d *Devbox) ensurePackagesAreInstalled(ctx context.Context, mode installMode) error {
 	defer trace.StartRegion(ctx, "ensurePackages").End()
 	defer debug.FunctionTimer().End()
@@ -248,8 +256,10 @@ func (d *Devbox) ensurePackagesAreInstalled(ctx context.Context, mode installMod
 		return err
 	}
 
-	// Force print-dev-env cache to be recomputed.
-	nixEnv, err := d.computeNixEnv(ctx, false /*use cache*/)
+	// Use the printDevEnvCache if we are adding or removing or updating any package,
+	// AND we are not in the shellenv-enabled environment of the current devbox-project.
+	usePrintDevEnvCache := mode != ensure && !d.IsEnvEnabled()
+	nixEnv, err := d.computeNixEnv(ctx, usePrintDevEnvCache)
 	if err != nil {
 		return err
 	}
@@ -291,8 +301,8 @@ func (d *Devbox) profilePath() (string, error) {
 	return absPath, errors.WithStack(os.MkdirAll(filepath.Dir(absPath), 0o755))
 }
 
-// syncPackagesToProfile ensures that all packages in devbox.json exist in the nix profile,
-// and no more.
+// syncPackagesToProfile can ensure that all packages in devbox.json exist in the nix profile,
+// and no more. However, it may skip some steps depending on the `mode`.
 func (d *Devbox) syncPackagesToProfile(ctx context.Context, mode installMode) error {
 	defer debug.FunctionTimer().End()
 	defer trace.StartRegion(ctx, "syncPackagesToProfile").End()
@@ -320,9 +330,12 @@ func (d *Devbox) syncPackagesToProfile(ctx context.Context, mode installMode) er
 	}
 
 	// Second, remove any packages from the nix-profile that are not in the config
-	itemsToKeep, err := d.removeExtraItemsFromProfile(ctx, profileDir, profileItems, packages)
-	if err != nil {
-		return err
+	itemsToKeep := profileItems
+	if mode != install {
+		itemsToKeep, err = d.removeExtraItemsFromProfile(ctx, profileDir, profileItems, packages)
+		if err != nil {
+			return err
+		}
 	}
 
 	// we are done if mode is uninstall
diff --git a/internal/impl/shell_test.go b/internal/impl/shell_test.go
index 98255ef2b79..6813f4a443a 100644
--- a/internal/impl/shell_test.go
+++ b/internal/impl/shell_test.go
@@ -17,8 +17,8 @@ import (
 	"go.jetpack.io/devbox/internal/shellgen"
 )
 
-// update overwrites golden files with the new test results.
-var update = flag.Bool("update", false, "update the golden files with the test results")
+// updateFlag overwrites golden files with the new test results.
+var updateFlag = flag.Bool("update", false, "update the golden files with the test results")
 
 func TestWriteDevboxShellrc(t *testing.T) {
 	testdirs, err := filepath.Glob("testdata/shellrc/*")
@@ -83,7 +83,7 @@ func testWriteDevboxShellrc(t *testing.T, testdirs []string) {
 			// Overwrite the golden file if the -update flag was
 			// set, and then proceed normally. The test should
 			// always pass in this case.
-			if *update {
+			if *updateFlag {
 				err = os.WriteFile(test.goldShellrcPath, gotShellrc, 0o666)
 				if err != nil {
 					t.Error("Error updating golden files:", err)
diff --git a/internal/impl/update.go b/internal/impl/update.go
index 9679059b7d8..69064e18f97 100644
--- a/internal/impl/update.go
+++ b/internal/impl/update.go
@@ -62,7 +62,7 @@ func (d *Devbox) Update(ctx context.Context, opts devopt.UpdateOpts) error {
 		}
 	}
 
-	if err := d.ensurePackagesAreInstalled(ctx, ensure); err != nil {
+	if err := d.ensurePackagesAreInstalled(ctx, update); err != nil {
 		return err
 	}
 
diff --git a/trace.out b/trace.out
new file mode 100644
index 00000000000..a3a65f653f9
Binary files /dev/null and b/trace.out differ