gitindex: disable git cat-file optimization by default (#1038)

In our production sourcegraph.com cluster we are regularly seeing git
grow to over 9GB in size leading to OOMs. Once we disabled this flag the
OOMs went away. For now lets default this feature to off until it is
resolved.

Author: keegancsmith

gitindex/index.go

@@ -619,7 +619,11 @@ func indexGitRepo(opts Options, config gitIndexConfig) (bool, error) {
 	// for the main repo so we can stream them via git cat-file --batch.
 	// ZOEKT_DISABLE_CATFILE_BATCH=true falls back to the go-git path for
 	// all files, useful as a kill switch if the cat-file path causes issues.
-	catfileBatchDisabled := cmp.Or(os.Getenv("ZOEKT_DISABLE_CATFILE_BATCH"), "false")
+	//
+	// 2026-04-02(keegan) we are regularly seeing git growing to over 9GB in
+	// memory usage in our production cluster. Disabling by default until the
+	// issue is resolved.
+	catfileBatchDisabled := cmp.Or(os.Getenv("ZOEKT_DISABLE_CATFILE_BATCH"), "true")
 	useCatfileBatch := true
 	if disabled, _ := strconv.ParseBool(catfileBatchDisabled); disabled {
 		useCatfileBatch = false