Memory leaks, from Igor Wong in GitHub issue 1934.

cmd-parse.y

@@ -696,6 +696,7 @@ cmd_parse_build_commands(struct cmd_parse_commands *cmds,
 			pr.status = CMD_PARSE_ERROR;
 			pr.error = cmd_parse_get_error(pi->file, line, cause);
 			free(cause);
+			cmd_list_free(cmdlist);
 			goto out;
 		}
 		cmd_list_append(cmdlist, add);

options.c

@@ -296,6 +296,7 @@ options_remove(struct options_entry *o)
 	else
 		options_value_free(o, &o->value);
 	RB_REMOVE(options_tree, &oo->tree, o);
+	free((void *)o->name);
 	free(o);
 }
 

tmux.c

@@ -130,6 +130,7 @@ make_label(const char *label, char **cause)
 		free(base);
 		goto fail;
 	}
+	free(base);
 
 	if (mkdir(resolved, S_IRWXU) != 0 && errno != EEXIST)
 		goto fail;