Segfault in XAIGER

[Periodic1911]

Version

Yosys 0.46+11 (git sha1 0200a76, g++ 14.2.1 -march=x86-64 -mtune=generic -O2 -fno-plt -fexceptions -fstack-clash-protection -fcf-protection -fPIC -O3)

On which OS did this happen?

Linux

Reproduction Steps

Make a file test.v with:

module test(input [1:0] a, b,
            input c,
            output [1:0] q); 

wire s;
assign s = c ? q[0] : q[1];
assign q = s ? a : b;

endmodule

And run yosys -p "synth_ice40" test.v

FWIW, it does not segfault when you swap the assign statements.

Expected Behavior

Either an error because of a logic loop or a synthesized design. Not a segfault, in any case.

Actual Behavior

Segfault in the XAIGER backend.

...

2.41.13.3. Executing XAIGER backend.
Segmentation fault (core dumped)

Full output: https://gist.github.com/Periodic1911/3618ee7299c6f9f69e6e32a9a547c4b9