Subject: Re: bug#39575: guix time-machine fails when a tarball was modified in-place

From: Tobias Geerinckx-Rice <[email-masked]>
Date: Sat, 15 Feb 2020 21:01:36 +0100

Jan, Simon,

Janneke 写道：
> https://snapshot.debian.org/archive/debian/20190406T212022Z/pool/main/h/harfbuzz/harfbuzz_2.4.0.orig.tar.bz2

This is a wonderful resource!  Thank you, Janneke (and Debian)!

zimoun 写道：
> Cool!
> But how do you determine the "date", i.e., this reference 
> '20190406T212022Z' ?

You'd take the timestamp immediately preceding your desired (Guix) 
commit's date, or something like that.  The fact that git commit 
dates aren't linear shouldn't hurt here.

> Could it be automated?

Not without parsing HTML to get the valid timestamps: 
<https://snapshot.debian.org/archive/debian/?year=2020&month=2>.

Also, this doesn't seem to be a supported service yet[0]:

  “This is an implementation for a possible snapshot.debian.org 
  service.
   It's not yet finished, it's more a prototype/proof of concept 
   to show
   and learn what we want and can provide.  So far it seems to 
   actually work.”

Still really cool,

T G-R

[0]: https://salsa.debian.org/snapshot-team/snapshot