-package-name flag in 6.10.x

Duncan Coutts duncan.coutts at googlemail.com
Wed Nov 25 04:31:14 EST 2009

On Wed, 2009-11-25 at 04:56 +0000, Malcolm Wallace wrote:
> Moreover, when I attempt to use the flag, like so:
>      $ ghc -package-name hat-2.06 ...
>      <command line>: cannot parse 'hat-2.06' as a package identifier
> This used to work with ghc-6.6.x and ghc-6.8.x, but seems to have  
> stopped working with ghc-6.10.x.  I surmise that the leading zero  
> after the version point separator is to blame?  It seems an  
> unfortunate regression.

On the contrary, it is good that it checks this now. The package name
compiled into the code really ought to match the package name registered
with ghc-pkg and the latter is a package identifier, not an arbitrary

In principle it would be possible to parse 2.06 as a Version [2,6],
however I think we decided that allowing that redundancy in the original
string is not a good idea since people might expect 2.6 and 2.06 to be
different. It would also mean we could not rely on lossless round trips
between parser and printer which would be annoying for things like
finding the file or directory containing a package (imagine we go
looking for "2.6/" when the files are really in "2.06/").


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