Re: [PATCH] Improve ant-build-system.

[Ricardo Wurmus <ricardo.wurmus@mdc-berlin.de>]

Leo Famulari <leo@famulari.name> writes:

> On Thu, Mar 24, 2016 at 03:50:38PM +0100, Ricardo Wurmus wrote:
>> Hi Guix,
>> 
>> our ant-build-system currently throws away the jar manifest, because it
>> was difficult to control its timestamp.  Without a manifest many jars
>> cannot be used, though.  Oops!
>> 
>> The manifest and the directory it is in always get the current time,
>> which is very annoying.  Since controlling the timestamp is not possible
>> with “jar”, this patch repacks the jar archive with “zip”.  The only
>> thing we need to take care of is to ensure that the manifest file
>> appears first.
>
> So, the timestamp issue is avoided by using "zip"? Just curious, I would
> want to block this change regardless.

Correct.  “jar” doesn’t just create an archive, it also sets the
timestamp of the manifest.  “zip” doesn’t care about manifest timestamps
and will just take the files as they are.  Since we reset timestamps of
all files in the archive this means that the manifest will have the same
timestamp as any other file in the archive.  This makes the jar archive
reproducible.

~~ Ricardo