scalar: add retry logic to run_git()

Use a fixed 3 tries total to see how that increases our chances of
success for subcommands such as 'git fetch'.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>

scalar.c

@@ -70,20 +70,25 @@ static void setup_enlistment_directory(int argc, const char **argv,
 	strbuf_release(&path);
 }
 
+static int git_retries = 3;
+
 static int run_git(const char *arg, ...)
 {
 	struct strvec argv = STRVEC_INIT;
 	va_list args;
 	const char *p;
-	int res;
+	int res, attempts;
 
 	va_start(args, arg);
 	strvec_push(&argv, arg);
 	while ((p = va_arg(args, const char *)))
 		strvec_push(&argv, p);
 	va_end(args);
 
-	res = run_command_v_opt(argv.v, RUN_GIT_CMD);
+	for (attempts = 0, res = 1;
+	     res && attempts < git_retries;
+	     attempts++)
+		res = run_command_v_opt(argv.v, RUN_GIT_CMD);
 
 	strvec_clear(&argv);
 	return res;