[nix.System] call EnsureNixInstalled from devbox.Open, and cleanup function API

Author: savil

internal/devconfig/packages.go

@@ -243,7 +243,7 @@ func NewPackage(name string, values map[string]any) Package {
 // If the package has a list of excluded platforms, it is enabled on all platforms
 // except those.
 func (p *Package) IsEnabledOnPlatform() bool {
-	platform := nix.MustGetSystem()
+	platform := nix.System()
 	if len(p.Platforms) > 0 {
 		for _, plt := range p.Platforms {
 			if plt == platform {

internal/devpkg/package.go

@@ -227,12 +227,8 @@ func (p *Package) NormalizedDevboxPackageReference() (string, error) {
 	}
 
 	if path != "" {
-		s, err := nix.System()
-		if err != nil {
-			return "", err
-		}
 		url, fragment, _ := strings.Cut(path, "#")
-		return fmt.Sprintf("%s#legacyPackages.%s.%s", url, s, fragment), nil
+		return fmt.Sprintf("%s#legacyPackages.%s.%s", url, nix.System(), fragment), nil
 	}
 
 	return "", nil
@@ -480,17 +476,12 @@ func (p *Package) IsInBinaryCache() (bool, error) {
 		return false, err
 	}
 
-	userSystem, err := nix.System()
-	if err != nil {
-		return false, err
-	}
-
 	if entry.Systems == nil {
 		return false, nil
 	}
 
 	// Check if the user's system's info is present in the lockfile
-	_, ok := entry.Systems[userSystem]
+	_, ok := entry.Systems[nix.System()]
 	if !ok {
 		return false, nil
 	}
@@ -519,12 +510,7 @@ func (p *Package) InputAddressedPath() (string, error) {
 		return "", err
 	}
 
-	userSystem, err := nix.System()
-	if err != nil {
-		return "", err
-	}
-
-	sysInfo := entry.Systems[userSystem]
+	sysInfo := entry.Systems[nix.System()]
 	return sysInfo.StorePath, nil
 }
 

internal/impl/devbox.go

@@ -73,6 +73,7 @@ type Devbox struct {
 var legacyPackagesWarningHasBeenShown = false
 
 func Open(opts *devopt.Opts) (*Devbox, error) {
+
 	projectDir, err := findProjectDir(opts.Dir)
 	if err != nil {
 		return nil, err
@@ -128,6 +129,10 @@ func Open(opts *devopt.Opts) (*Devbox, error) {
 		)
 	}
 
+	if err := nix.EnsureNixInstalled(box.writer, nil); err != nil {
+		return nil, err
+	}
+
 	return box, nil
 }
 

internal/impl/update.go

@@ -126,15 +126,12 @@ func (d *Devbox) mergeResolvedPackageToLockfile(
 
 	// Add any missing system infos for packages whose versions did not change.
 	if featureflag.RemoveNixpkgs.Enabled() {
-		userSystem, err := nix.System()
-		if err != nil {
-			return err
-		}
 
 		if lockfile.Packages[pkg.Raw].Systems == nil {
 			lockfile.Packages[pkg.Raw].Systems = map[string]*lock.SystemInfo{}
 		}
 
+		userSystem := nix.System()
 		updated := false
 		for sysName, newSysInfo := range resolved.Systems {
 			if sysName == userSystem {

internal/impl/update_test.go

@@ -157,7 +157,6 @@ func TestUpdateOtherSysInfoIsReplaced(t *testing.T) {
 }
 
 func currentSystem(t *testing.T) string {
-	sys, err := nix.System() // NOTE: we could mock this too, if it helps.
-	require.NoError(t, err)
+	sys := nix.System() // NOTE: we could mock this too, if it helps.
 	return sys
 }

internal/lock/resolve.go

@@ -61,11 +61,7 @@ func (f *File) FetchResolvedPackage(pkg string) (*Package, error) {
 }
 
 func selectForSystem(pkg *searcher.PackageVersion) (searcher.PackageInfo, error) {
-	currentSystem, err := nix.System()
-	if err != nil {
-		return searcher.PackageInfo{}, err
-	}
-	if pi, ok := pkg.Systems[currentSystem]; ok {
+	if pi, ok := pkg.Systems[nix.System()]; ok {
 		return pi, nil
 	}
 	if pi, ok := pkg.Systems["x86_64-linux"]; ok {

internal/nix/install.go

@@ -99,7 +99,7 @@ func EnsureNixInstalled(writer io.Writer, withDaemonFunc func() *bool) (err erro
 	defer func() {
 		if err == nil {
 			// call System to ensure its value is internally cached so we can rely on MustGetSystem
-			_, err = System()
+			_ = System()
 		}
 	}()
 

internal/nix/nix.go

@@ -118,23 +118,21 @@ func ExperimentalFlags() []string {
 	}
 }
 
-// TODO: rename to System
-func MustGetSystem() string {
+func System() string {
 	if cachedSystem == "" {
-		// For internal calls (during tests), this may not be initialized properly
-		// so do a best-effort attempt to initialize it.
-		_, err := System()
+		// While this should have been initialized, we do a best-effort to avoid
+		// a panic.
+		_, err := ComputeSystem()
 		if err != nil {
-			panic("MustGetSystem called before being initialized by System")
+			panic("System called before being initialized by ComputeSystem")
 		}
 	}
 	return cachedSystem
 }
 
 var cachedSystem string
 
-// TODO: rename to ComputeSystem or ComputePlatform?
-func System() (string, error) {
+func ComputeSystem() (string, error) {
 	// For Savil to debug "remove nixpkgs" feature. The Search api lacks x86-darwin info.
 	// So, I need to fake that I am x86-linux and inspect the output in generated devbox.lock
 	// and flake.nix files.
@@ -151,7 +149,7 @@ func System() (string, error) {
 		cmd.Args = append(cmd.Args, ExperimentalFlags()...)
 		out, err := cmd.Output()
 		if err != nil {
-			return "", errors.WithStack(err)
+			return "", err
 		}
 		cachedSystem = string(out)
 	}

internal/nix/nixprofile/profile.go

@@ -265,12 +265,7 @@ func ProfileInstall(args *ProfileInstallArgs) error {
 		if exists, err := input.ValidateInstallsOnSystem(); err != nil {
 			return err
 		} else if !exists {
-			platform, err := nix.System()
-			if err != nil {
-				platform = ""
-			} else {
-				platform = " " + platform
-			}
+			platform := " " + nix.System()
 			return usererr.New(
 				"package %s cannot be installed on your platform%s. "+
 					"Run `devbox add %[1]s --exclude-platform%[2]s` and re-try.",

internal/plugin/plugin.go

@@ -142,11 +142,6 @@ func (m *Manager) createFile(
 		return errors.WithStack(err)
 	}
 
-	system, err := nix.System()
-	if err != nil {
-		return err
-	}
-
 	var urlForInput, attributePath string
 
 	if pkg, ok := pkg.(*devpkg.Package); ok {
@@ -164,7 +159,7 @@ func (m *Manager) createFile(
 		"DevboxProfileDefault": filepath.Join(m.ProjectDir(), nix.ProfilePath),
 		"PackageAttributePath": attributePath,
 		"Packages":             m.PackageNames(),
-		"System":               system,
+		"System":               nix.System(),
 		"URLForInput":          urlForInput,
 		"Virtenv":              filepath.Join(virtenvPath, name),
 	}); err != nil {