Give a better error message if trying to pbuilder a .changes file

[Bryce Harrington]

Binary package hint: pbuilder

A common mistake I make when running pbuilder is to specify the .changes file instead of the .dsc. Probably because my fingers are trained that the .changes is the "important" file (since it's what I'll be uploading).

Unfortunately, pbuilder generates a very confusing and unfriendly set of error messages when you give it a .changes file instead of a .dsc file, and it's not at all clear that the problem is that you gave it the wrong kind of file.

I'd like to see pbuilder be given a clearer error message when this happens. Maybe something like,

    Error: <whatever>.changes is not in the right format (did you mean to build <whatever>.dsc?)

What would be even more slick would be if pbuilder could DoWhatIMean, and figure out the .dsc from the .changes filename, and pbuilder it. But at least giving a sane error message would be a step in the right direction.

[Maarten Bezemer (veger)]

Version 0.204 gives a good/better error when a .changes file is accidentally used:
  E: Command line parameter [<whatever>.changes] is not a valid .dsc file name

At least, the suggestion that a dsc file should be used is showed.

[Maarten Bezemer (veger)]

Version 0.206 gives this error:
  E: Command line parameter [<whatever>.changes] is does not exist

See http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=644507

So upgrading to 0.206 gives an even better error message

[Maarten Bezemer (veger)]

I found a minor typo in the error message: 'is' should be removed.
So I send a bug report + patch to debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=659703