always recompute Devbox environment, and reuse buildInputs from print-dev-env output

Author: savil

internal/devbox/nixprofile.go

@@ -2,7 +2,6 @@ package devbox
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"strings"
 
@@ -12,39 +11,31 @@ import (
 
 // syncFlakeToProfile ensures the buildInputs from the flake's devShell are
 // installed in the nix profile.
-func (d *Devbox) syncFlakeToProfile(ctx context.Context) error {
+// buildInputs is a space-separated list of store paths from the nix print-dev-env output's buildInputs.
+func (d *Devbox) syncFlakeToProfile(ctx context.Context, buildInputs string) error {
 	profilePath, err := d.profilePath()
 	if err != nil {
 		return err
 	}
 
-	// Get the build inputs (i.e. store paths) from the generated flake's devShell.
-	buildInputPaths, err := nix.Eval(
-		ctx,
-		d.stderr,
-		d.flakeDir()+"#devShells."+nix.System()+".default.buildInputs",
-		"--json",
-	)
-	if err != nil {
-		return fmt.Errorf("nix eval devShells: %v", err)
-	}
-	storePaths := []string{}
-	if err := json.Unmarshal(buildInputPaths, &storePaths); err != nil {
-		return fmt.Errorf("unmarshal store paths: %s: %v", buildInputPaths, err)
+	// Get the build inputs (i.e. store paths) from the generated flake's print-dev-env output
+	wantStorePaths := []string{}
+	if buildInputs != "" { // if buildInputs is empty, then we don't want wantStorePaths to be an array with a single "" entry
+		wantStorePaths = strings.Split(buildInputs, " ")
 	}
 
 	// Get the store-paths of the packages currently installed in the nix profile
 	items, err := nixprofile.ProfileListItems(ctx, d.stderr, profilePath)
 	if err != nil {
 		return fmt.Errorf("nix profile list: %v", err)
 	}
-	got := make([]string, 0, len(items))
+	gotStorePaths := make([]string, 0, len(items))
 	for _, item := range items {
-		got = append(got, item.StorePaths()...)
+		gotStorePaths = append(gotStorePaths, item.StorePaths()...)
 	}
 
 	// Diff the store paths and install/remove packages as needed
-	add, remove := diffStorePaths(got, storePaths)
+	add, remove := diffStorePaths(gotStorePaths, wantStorePaths)
 	if len(remove) > 0 {
 		packagesToRemove := make([]string, 0, len(remove))
 		for _, p := range remove {

internal/devbox/packages.go

@@ -292,17 +292,15 @@ func (d *Devbox) ensureStateIsUpToDate(ctx context.Context, mode installMode) er
 		return err
 	}
 
-	// Skip the print-dev-env's cache if we are in a devbox-environment. If not,
-	// skip the cache if we're either installing packages or ensuring
-	// the project state is up-to-date.
-	skipPrintDevEnvCache := true
-	// skipPrintDevEnvCache := d.IsEnvEnabled() || (mode == ensure || mode == install)
-	if _, err := d.computeEnv(ctx, !skipPrintDevEnvCache /*usePrintDevEnvCache*/); err != nil {
+	// Always re-compute print-dev-env to ensure all packages are installed, and
+	// the correct set of packages are reflected in the nix-profile below.
+	env, err := d.computeEnv(ctx, false /*usePrintDevEnvCache*/)
+	if err != nil {
 		return err
 	}
 
 	// Ensure the nix profile has the packages from the flake.
-	if err := d.syncFlakeToProfile(ctx); err != nil {
+	if err := d.syncFlakeToProfile(ctx, env["buildInputs"]); err != nil {
 		return err
 	}