[License-review] Submission of the European Space Agency Public Licenses (ESA-PL) for approval

[Carsten Gerlach]

On 10.01.2017 19:38, Tzeng, Nigel H. wrote:
> While we generate such a file to meet the NOSA 1.3 Section 1.C
> requirements using:
> 
> 
> git log  --all --pretty=format:"%ad %d %s (%aN)"
> 
> 
> it would be more helpful if one could simply provide the git repo of all
> the source changes and allow the user to peruse the change history in any
> manner they wish.
> 
> Even with the log it doesn¹t identify which lines we changed in what
> files.  If anyone wishes to determine the provenance of any given
> file/line/class the log file by itself wouldn¹t let them do soŠthey¹d
> still want a copy of the repo.  Or an annoying diff file.
> 
> I understand the desire and need to document these changes.  I would
> prefer a less prescriptive manner in fulfilling these requirements.

Less formal requirements and less obligations are of course preferable.
But often the distribution or redistribution is not made by simply
providing a link to the git repo, but by creating and distributing a
snapshot of the latest version, e.g. as a tgz. In that case, the history
information would be lost. With a changelog file the recipients still
retain access to the version history.

In addition, the changelog file is usually not diff output or a list of
commits, but a manually generated  "high level" overview of changes –
and therefore makes it easier for users to see what notable changes have
been made. However, this is not a requirement of the license, but as far
as I know only a best practice.

I don't think the obligation to maintain a changelog is too onerous.
Similar obligations are found in a lot of OSS licenses. As you've said,
you could simply auto-generate the changelog, if you don't want to
invest the effort to manually maintain it

> I assume that when we deliver flight or instrument software that we don¹t
> have to include the changelog file with the copy of the software aboard
> the spacecraft itself. :)

I am not even sure if this scenario constitutes a distribution which
would require inclusion of a changelog file...

Carsten