opt out of accursedUnutterablePerformIO

[Ben Franksen]

Am 04.03.2018 um 11:19 schrieb Ben Franksen:
> That still leaves the question of how users can make their project
> depend on a bytestring that has been built with this flag. I know this
> can be done with manual installation of a new version of the library,
> but I would rather use cabal new-build (as I am used to) and let it
> figure out itself that it has to attach a new hash to the variant with
> the flag.

Looking at the file generated by cabal new-freeze make it pretty clear
how to set flags for dependencies (and apparently cabal does make use of
this for a number of packages).

Cheers
Ben