Verilator

Verilator 3.820 devel rev verilator_3_820-2-gdf1da3d aborts with an internal error when casting is used. For example, the following code

module cast_issue(input clk, input [4:0] a);
    integer i;

    always @(posedge clk)
        i <= integer'(a);
endmodule

causes verilator to bail out with the message

%Error: Internal Error: cast_issue.v:5: ../V3Ast.cpp:494: Node has no back, already unlinked?
%Error: Internal Error: See the manual and http://www.veripool.org/verilator for more assistance.
%Error: Command Failed verilator_bin --sp cast_issue.v

The problem is the same with user defined types. This used to work fine in version 3.814