Arithmetization stucks in an infinite loop when marking a variable as constant (using Groth16 with the `constraints` module)

[ilitteri]

The bug is better explained in the section "Infinite loop during the arithmetization" of this post. But the TLDR is that if your mark a variable as constant using MarkConstant() when building an R1CS and Groth16, the AddConstraint call runs infinitely.

A detailed explanation for this issue is written here.