fix: gracefully handle process metrics registration failure on unsupported OSes

.chloggen/fix-aix-crash.yaml

@@ -0,0 +1,4 @@
+change_type: bug_fix
+component: pkg/service
+note: "Don't error on startup when process metrics are enabled on unsupported OSes (e.g. AIX)"
+issues: [14307]

service/processmetrics_others.go

@@ -0,0 +1,20 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build !linux && !windows && !darwin
+
+package service // import "go.opentelemetry.io/collector/service"
+
+import (
+	"runtime"
+
+	"go.uber.org/zap"
+)
+
+func registerProcessMetrics(srv *Service) error {
+	srv.telemetrySettings.Logger.Warn(
+		"Process metrics are disabled on this operating system",
+		zap.String("os", runtime.GOOS),
+	)
+	return nil
+}

service/processmetrics_valid.go

@@ -0,0 +1,19 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build linux || windows || darwin
+
+package service // import "go.opentelemetry.io/collector/service"
+
+import (
+	"fmt"
+
+	"go.opentelemetry.io/collector/service/internal/proctelemetry"
+)
+
+func registerProcessMetrics(srv *Service) error {
+	if err := proctelemetry.RegisterProcessMetrics(srv.telemetrySettings); err != nil {
+		return fmt.Errorf("failed to register process metrics: %w", err)
+	}
+	return nil
+}

service/service.go

@@ -29,7 +29,6 @@ import (
 	"go.opentelemetry.io/collector/service/internal/graph"
 	"go.opentelemetry.io/collector/service/internal/metricviews"
 	"go.opentelemetry.io/collector/service/internal/moduleinfo"
-	"go.opentelemetry.io/collector/service/internal/proctelemetry"
 	"go.opentelemetry.io/collector/service/internal/status"
 	"go.opentelemetry.io/collector/service/telemetry"
 )
@@ -223,9 +222,11 @@ func New(ctx context.Context, set Settings, cfg Config) (_ *Service, resultErr e
 		return nil, err
 	}
 
-	if err := proctelemetry.RegisterProcessMetrics(srv.telemetrySettings); err != nil {
-		return nil, fmt.Errorf("failed to register process metrics: %w", err)
+	// Register process metrics (build-tagged per OS).
+	if err := registerProcessMetrics(srv); err != nil {
+		return nil, err
 	}
+
 	return srv, nil
 }