racket does not support MPFR on ubuntu 18.10

[bozherbie]

Hello,

In ubuntu 18.10, I dit not manage to get MPFR support in racket:
With the default racket package:

 racket 
Welcome to Racket v6.12.
> (require math/bigfloat)
> (bf 1)
; mpfr_set_nan: implementation not found; arguments: #<_mpfr> [,bt for context]
>  (exit)

With this ppa : https://launchpad.net/~plt/+archive/ubuntu/racket

racket 
racket 
Welcome to Racket v7.1.
> (require math/bigfloat)
> (bf 1)
; mpfr_set_nan: implementation not found; arguments: #<_mpfr> [,bt for context]
> (exit)

Note that ibmpfr6 seems to be installed:

Sorting... Done
Full Text Search... Done
libmpfr6/cosmic,now 4.0.1-1 amd64 [installed,automatic]
  multiple precision floating-point computation

I discovered this bug while trying to get herbie working on my computer: herbie-fp/herbie#211

[samth]

I moved this to the racket/math repository. I think something needs to be added here: https://github.com/racket/math/blob/master/math-lib/math/private/bigfloat/mpfr.rkt#L68-L74, perhaps the version 4.0.1 but I'm not sure.

[pavpanchekha]

I've had the same issue reported to me by other users of Herbie, all on 18.10, in case it helps.

[pavpanchekha]

MPFR released a new version on 31 December 2018, and I hear the Ubuntu repository has been updated as well. @bozherbie, could you check whether a package update fixes this issue?

[billzorn]

I just had this same issue on Ubuntu 18.04.2; it was fixed by installing libmpfr-dev. libmpfr6 was already installed, but that seemed to be insufficient without the headers.