On 11/16/2017 5:28 PM, TOM wrote:
Recently, I acquired a batch of commits’ SHA data of Lucene, of which the
time span is from 2010 to 2015. In order to get original info, I tried to use
these SHA data to track commits.
<snip>
In summary, 1) did the method to generate SHA num of commit change once before?
2) because the second mirror repository ended its update since 2014, how can I
track the whole commits of my dataset?
When you asked this same question on November 9th (and even earlier on
the dev list), I replied with this information, and what I told you was
confirmed by Chris Hostetter.
Yes, all of the SHA data in the github repository *has* changed. This
event happened in early to mid January 2016.
At that time, the Lucene/Solr project migrated the source repository
from subversion to git. Before this, the github mirror was (as stated
by Chris), an automated realtime git->svn conversion set up by Apache
Infra. It was actually the github mirror that forced our hand to
complete our own repository migration -- that realtime svn->git
conversion was requiring so many resources that it was crashing the
conversion process for other projects. Infra was going to turn the
conversion of our repository off, and we would no longer *have* an
up-to-date github mirror. As a project, we had been discussing the
conversion already, but it was that problem that pushed people into action.
The official conversion of the repository from svn to git produced a
repository with entirely different commit SHA values than the old github
mirror, and we couldn't use it to maintain that mirror. The github
mirror that matched your commit data was completely deleted, and then
rebuilt as a true mirror of the official git repository.
The commit data you're using is nearly useless, because the repository
where it originated has been gone for nearly two years. If you can find
out how it was generated, you can build a new version from the current
repository -- either on github or from Apache's official servers.
Thanks,
Shawn
