Check OS X version to decide if sandbox is supported.

--
MOS_MIGRATED_REVID=132570504

src/main/java/com/google/devtools/build/lib/sandbox/DarwinSandboxRunner.java

@@ -20,6 +20,7 @@
 import com.google.devtools.build.lib.shell.CommandException;
 import com.google.devtools.build.lib.shell.KillableObserver;
 import com.google.devtools.build.lib.shell.TimeoutKillableObserver;
+import com.google.devtools.build.lib.util.OS;
 import com.google.devtools.build.lib.vfs.Path;
 import java.io.File;
 import java.io.IOException;
@@ -58,6 +59,24 @@ final class DarwinSandboxRunner extends SandboxRunner {
   }
 
   static boolean isSupported() {
+    // Check osx version, only >=10.11 is supported.
+    // And we should check if sandbox still work when it gets 11.x
+    String osxVersion = OS.getVersion();
+    String[] parts = osxVersion.split("\\.");
+    if (parts.length != 3) {
+      // Currently the format is 10.11.x
+      return false;
+    }
+    try {
+      int v0 = Integer.parseInt(parts[0]);
+      int v1 = Integer.parseInt(parts[1]);
+      if (v0 != 10 || v1 < 11) {
+        return false;
+      }
+    } catch (NumberFormatException e) {
+      return false;
+    }
+
     List<String> args = new ArrayList<>();
     args.add(SANDBOX_EXEC);
     args.add("-p");

src/main/java/com/google/devtools/build/lib/util/OS.java

@@ -42,6 +42,10 @@ public String getCanonicalName() {
     return canonicalName;
   }
 
+  public static String getVersion() {
+    return System.getProperty("os.version");
+  }
+
   @Override
   public String toString() {
     return getCanonicalName();
@@ -55,7 +59,7 @@ private static OS determineCurrentOs() {
       osName = System.getProperty("os.name");
     }
 
-    if (osName == null) { 
+    if (osName == null) {
       return OS.UNKNOWN;
     }