Bug#359989: apt: [apt-get source] fails if dpkg-source is not installed

[Jari Aalto <jari.aalto@cante.net>]

| On Thu, Mar 30, 2006 at 12:23:45AM +0200, Jari Aalto wrote:
| > Package: apt
| > Version: 0.6.43.3
| > Severity: normal
| 
| Thanks for your bugreport.
| 
| [..] 
| >     test:/tmp# apt-get source jwm
| >     Reading Package Lists... Done
| >     Building Dependency Tree... Done
| >     Need to get 331kB of source archives.
| >     Get:1 http://debian.cante.net stable/main jwm 1.1-1 (dsc) [337B]
| >     Get:2 http://debian.cante.net stable/main jwm 1.1-1 (tar) [331kB]
| >     Fetched 331kB in 0s (397kB/s)
| >     sh: dpkg-source: not found
| >     Unpack command 'dpkg-source -x jwm_1.1-1.dsc' failed.
| >     E: Child process failed
| > 
| > SUGGESTION
| > 
| > It would be better if apt checked the existence of dpkg-source before
| > attempting download and notify user to install dpkg-dev package.
| 
| The error message in the latest apt is:
|  _("Unpack command '%s' failed.\n"),S);
|  _("Check if the 'dpkg-dev' package is installed.\n"));
| 
| This should be sufficient IMHO. I don't think the command should fail
| before the download because having the source available may be still
| helpful and a subsequent apt-get source (after install dpkg-dev)
| should do the right thing and unpack the source.

Erm, this looks like backwards A:

     1. run apt-get just to see it fail
     2. install additional package
     2. re-run apt-get to make it work

When B: 

     1. run apt-get, refuse to continue, because
        preliminary setup is not satisfied
        (missing command dpkg-source)

Catching errors as early as possible is considered
much better from usability perspective.

Adding a check if dpkg-source is in PATH should
be real trivial.

The error message suggested:

   _("Check if the 'dpkg-dev' package is installed.\n"));

Is really helpful when combined with B. 

Jari