patch applied (cabal): Fix Show/Read for License

Duncan Coutts duncan.coutts at
Thu Dec 18 11:59:36 EST 2008

On Fri, 2008-12-12 at 11:50 -0800, Ian Lynagh wrote:
> Fri Dec 12 10:36:22 PST 2008  Ian Lynagh <igloo at>
>   * Fix Show/Read for License
>   We were ending up with things like
>       InstalledPackageInfo {
>           ...
>           license = LGPL Nothing,
>           ...
>       }
>   i.e. "LGPL Nothing" rather than "LGPL", which we couldn't then read.

I'd like to revert this patch. The serialisation format of
InstalledPackageInfo is defined by the Read/Show instance of the types.
GHC uses it's own faster parser but that just means it has to keep up,
not that we fix the format for all time.

It really should be LGPL Nothing because there is now an optional
version number on that license (and GPL).

Either we revert support for versioned licenses or we make GHC's parser
catch up. This half-way house is not workable (it looses information in
a read . show round trip).


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