fix nix.readManifest and nix search

internal/nix/profiles.go

@@ -94,8 +94,8 @@ func ProfileRemove(profilePath string, indexes ...string) error {
 
 type manifest struct {
 	Elements []struct {
-		Priority int `json:"priority"`
-	} `json:"elements"`
+		Priority int
+	}
 }
 
 func readManifest(profilePath string) (manifest, error) {
@@ -107,8 +107,37 @@ func readManifest(profilePath string) (manifest, error) {
 		return manifest{}, err
 	}
 
-	var m manifest
-	return m, json.Unmarshal(data, &m)
+	type manifestModern struct {
+		Elements map[string]struct {
+			Priority int `json:"priority"`
+		} `json:"elements"`
+	}
+	var modernMani manifestModern
+	if err := json.Unmarshal(data, &modernMani); err == nil {
+		// Convert to the result format
+		result := manifest{}
+		for _, e := range modernMani.Elements {
+			result.Elements = append(result.Elements, struct{ Priority int }{e.Priority})
+		}
+		return result, nil
+	}
+
+	type manifestLegacy struct {
+		Elements []struct {
+			Priority int `json:"priority"`
+		} `json:"elements"`
+	}
+	var legacyMani manifestLegacy
+	if err := json.Unmarshal(data, &legacyMani); err != nil {
+		return manifest{}, err
+	}
+
+	// Convert to the result format
+	result := manifest{}
+	for _, e := range legacyMani.Elements {
+		result.Elements = append(result.Elements, struct{ Priority int }{e.Priority})
+	}
+	return result, nil
 }
 
 const DefaultPriority = 5

internal/nix/search.go

@@ -98,15 +98,22 @@ func searchSystem(url, system string) (map[string]*Info, error) {
 		_ = EnsureNixpkgsPrefetched(writer, hash)
 	}
 
-	cmd := exec.Command("nix", "search", "--json", url)
+	// The `^` is added to indicate we want to show all packages
+	cmd := exec.Command("nix", "search", url, "^" /*regex*/, "--json")
 	cmd.Args = append(cmd.Args, ExperimentalFlags()...)
 	if system != "" {
 		cmd.Args = append(cmd.Args, "--system", system)
 	}
 	debug.Log("running command: %s\n", cmd)
 	out, err := cmd.Output()
 	if err != nil {
+		if exitErr := (&exec.ExitError{}); errors.As(err, &exitErr) {
+			err = fmt.Errorf("nix search exit code: %d, stderr: %s, original error: %w", exitErr.ExitCode(), exitErr.Stderr, err)
+		}
+
 		// for now, assume all errors are invalid packages.
+		// TODO: check the error string for "did not find attribute" and
+		// return ErrPackageNotFound only for that case.
 		return nil, fmt.Errorf("error searching for pkg %s: %w", url, err)
 	}
 	return parseSearchResults(out), nil