From 89a00819c42e7e5ec76ca06ab8ab968aa2e69324 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jean-S=C3=A9bastien=20P=C3=A9dron?=
 <jean-sebastien.pedron@dumbbell.fr>
Date: Wed, 27 Nov 2024 12:40:37 +0100
Subject: [PATCH] Work around race in `cover:is_compiled/1`

---
 src/horus.erl | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/horus.erl b/src/horus.erl
index f8e7794..dfcef3e 100644
--- a/src/horus.erl
+++ b/src/horus.erl
@@ -1998,7 +1998,7 @@ get_object_code(Module) ->
 %% @private
 
 do_get_object_code(Module) ->
-    case cover:is_compiled(Module) of
+    case is_cover_compiled(Module) of
         false ->
             get_object_code_from_code_server(Module);
         {file, Filename} ->
@@ -2008,6 +2008,18 @@ do_get_object_code(Module) ->
             erpc:call(CoverMainNode, ?MODULE, do_get_object_code, [Module])
     end.
 
+is_cover_compiled(Module) ->
+    try
+        cover:is_compiled(Module)
+    catch
+        error:{badmatch, {error, {already_started, _}}} ->
+            %% The code in `cover' that checks if the cover server is started
+            %% seem racy. We get an exception if it thinks it has to start it
+            %% but it is already started. In this case, we retry the call.
+            timer:sleep(100),
+            cover:is_compiled(Module)
+    end.
+
 get_object_code_from_code_server(Module) ->
     case code:get_object_code(Module) of
         {Module, Beam, Filename} ->