Bug#875992: haskell-lens: unsatisfiable B-D: libghc-vector-dev (< 0.12) but 0.12.0.1-1 is to be installed

[peter green]

There appears to be a new version in git that updates the package and fixes 
this build-dependency issue.

I presume the reason it hasn't been uploaded yet is 
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=875396