Does not build with integer-simple

[TomMD]

Or, more accurately, needlessly includes an integer-gmp build dep. This makes the code less portable for no notable gain.

I notice the code builds fine without the integer-gmp dependency - why is this included at all and what is the issue with removing it?

[depressed-pho]

It was OpenSSL.BN that had a dependency on integer-gmp for a performance reason. Now you can eliminate the dependency by configuring the package with --flags=-fast-bignum.