Only use objcopy in Linux environments quarkusio#13856

* `objcopy` invocations in macOS make the executable crash on startup.
* Debug info is only available for Linux,
so avoid `objcopy` altogether on macOS,
even if present in PATH.
* Updated documentation to avoid confusion.

core/deployment/src/main/java/io/quarkus/deployment/pkg/steps/NativeImageBuildLocalRunner.java

@@ -4,6 +4,8 @@
 import java.util.List;
 import java.util.stream.Stream;
 
+import org.apache.commons.lang3.SystemUtils;
+
 public class NativeImageBuildLocalRunner extends NativeImageBuildRunner {
 
     private final String nativeImageExecutable;
@@ -34,6 +36,10 @@ protected void objcopy(String... args) {
 
     @Override
     protected boolean objcopyExists() {
+        if (!SystemUtils.IS_OS_LINUX) {
+            return false;
+        }
+
         // System path
         String systemPath = System.getenv("PATH");
         if (systemPath != null) {

docs/src/main/asciidoc/building-native-image.adoc

@@ -703,7 +703,7 @@ Depending on what the final desired output of the CI/CD pipeline is, the generat
 
 Starting with Oracle GraalVM 20.2 or Mandrel 20.1,
 debug symbols for native executables can be generated for Linux environments
-(Windows support is still under development).
+(Windows support is still under development, macOS is not supported).
 These symbols can be used to debug native executables with tools such as `gdb`.
 
 To generate debug symbols,
@@ -713,17 +713,14 @@ You will find the debug symbols for the native executable in a `.debug` file nex
 [NOTE]
 ====
 The generation of the `.debug` file depends on `objcopy`.
-On common Linux distributions and macOS you will need to install the `binutils` package:
+On common Linux distributions you will need to install the `binutils` package:
 
 [source,bash]
 ----
 # dnf (rpm-based)
 sudo dnf install binutils
 # Debian-based distributions
 sudo apt-get install binutils
-# macOS
-brew install binutils
-export PATH=/usr/local/opt/binutils/bin:$PATH
 ----
 
 When `objcopy` is not available debug symbols are embedded in the executable.