Bug 1697098 - Default to --enable-bootstrap for arm64 mac builds. r=firefox-build-system-reviewers,andi,sheehan,mhentges

Differential Revision: https://phabricator.services.mozilla.com/D107601

moz.configure

@@ -208,9 +208,18 @@ def moz_fetches_dir(value):
         return value[0]
 
 
+@depends(host, milestone.is_nightly, "MOZ_AUTOMATION")
+def bootstrap_default(host, is_nightly, automation):
+    if automation:
+        return False
+    if host.cpu == "aarch64" and host.os == "OSX" and is_nightly:
+        return True
+
+
 option(
     "--enable-bootstrap",
-    help="Automatically bootstrap or update some toolchains",
+    default=bootstrap_default,
+    help="{Automatically bootstrap or update some toolchains|Disable bootstrap or update of toolchains}",
 )