We recently discovered that we had alignment issue in our code base, because we did not respect the guidelines in http://eigen.tuxfamily.org/dox-devel/gr ... ement.html
I'm thinking that we are most likely not the first nor the last to whom it happens. So there has to be some way to debug this without waiting for the code to crash. I'm thinking maybe a #define that would turn on runtime alignment checks and either assert or verbosely report where. This would slow things down, but we could turn on that flag on once in a while to sanitize our code.

Is there such facility? Or similar?

If you compile without -DNDEBUG then you should get such an assert.

I'm also in a similar situation. I have on old, stale project with lots of code written unfortunately without following those alignment instructions. Suddenly compiling without defining EIGEN_DONT_ALIGN_STATICALLY then I get memory violations.

There's a lot of code to sift through, so I'm looking for tips to debug this.

(edit: and not defining -DNDEBUG does not trigger any assertions...)

We have lot of advice in the following pages: http://eigen.tuxfamily.org/dox-devel/gr ... ement.html, but I'm really surprised that you don't get any runtime assertion as all statically aligned objects are checked at construction time. Is it related to libIGL so that I could give it a try myself?