Pin a package?

Shachaf Ben-Kiki shachaf at
Sat Jan 12 20:45:44 CET 2013

On Sat, Jan 12, 2013 at 11:25 AM, Stephen Paul Weber
<singpolyma at> wrote:
> Is there a way to tell cabal to refuse to upgrade a package?  I'd like to
> pin my `bytestring` to the version that shipped with my GHC.
> I just had a weird experience.  When I try to `cabal install iconv` (with my
> settings) it tried to downgrade my `bytestring`, when I download and do the
> configure+build by hand, it works, but when I try to install the local
> version it again begins to try to downgrade my bytestring.  If I just
> `register --inplace` it works fine.  Wut?

You can put "constraint: bytestring == version" in ~/.cabal/config.
Alternatively you can run one `cabal install --constraint "bytestring
== version"` command.


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