From b268f36b8f10186b9ac9e24d556e854183bcd328 Mon Sep 17 00:00:00 2001
From: ieQu1 <99872536+ieQu1@users.noreply.github.com>
Date: Thu, 2 Feb 2023 00:23:19 +0100
Subject: [PATCH] fix: Fix flaky t_core_node_down testcase

Fixes: #113
---
 src/mria_shards_sup.erl | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/mria_shards_sup.erl b/src/mria_shards_sup.erl
index 5b80f11..ba7093d 100644
--- a/src/mria_shards_sup.erl
+++ b/src/mria_shards_sup.erl
@@ -42,8 +42,15 @@ find_shard(Shard) ->
 -spec start_shard(mria_rlog:shard()) -> {ok, pid()}
                                       | {error, _}.
 start_shard(Shard) ->
-    Child = shard_sup(Shard),
-    supervisor:start_child(?SUPERVISOR, Child).
+    case whereis(?SUPERVISOR) of
+        undefined ->
+            %% FIXME: communicate via CVAR instead
+            timer:sleep(100),
+            start_shard(Shard);
+        _Pid ->
+            Child = shard_sup(Shard),
+            supervisor:start_child(?SUPERVISOR, Child)
+    end.
 
 %% @doc Restart a shard
 -spec restart_shard(mria_rlog:shard(), _Reason) -> ok.