On Tue, 1 Jun 2010, Erik Hesselink wrote:

On Tue, Jun 1, 2010 at 11:30 AM, Henning Thielemann

...

As far as I understand the problem is only a problem with an older version of Cabal and cabal-install. Is there a reason why you can't update your Cabal to a current version? I still do not feel encouraged to downgrade my package (and others with the Tested-With field). Alternatively you may modify the package privately and install it as say, data-accessor-0.2.1.3.1.

I have upgraded to cabal install 0.8 to solve this problem. However, many people still use 0.6, and it is included in distro's as well.

Additionally, the problem doesn't only occur when trying to install data-accessor, but also when installing something else that has data-accessor in its dependency tree anywhere, even if cabal-install finally decides it doesn't even need to install data-accessor (as it did in my case). This means even if you have data-accessor installed already, packages that depend on it (or depend on packages that depend on it, etc) fail to install.

It did already annoy me a lot, that cabal-install cannot just accept even successfully installed packages. But I think this is a problem of cabal-install not of data-accessor and other packages that use the Tested-With field.