esp 2.3.2 couldn't call tasks in other modules.
And sadly, the error message was:
Internal compiler error due to signal number 11 at or near line number 13 ... ESPCompiler ERROR.
As an example:
-------------------------------------------------- module dut; initial top.all_done; // Works initial all_done; // Doesn't work endmodule module top; task all_done; $finish; endtask dut dut (); endmodule --------------------------------------------------