Re: [BuildStream] [Summary] Plugin fragmentation / Treating Plugins as Sources

[Mathieu Bridon <bochecha daitauha fr>]

Hi,

On Thu, 2019-04-18 at 20:05 +0900, Tristan Van Berkom via buildstream-
list wrote:
> The `git` plugin origin
> ~~~~~~~~~~~~~~~~~~~~~~~
[… snip …]
>   * This proposal downloads unnecessary git history of plugin
>     repositories, and adds unnecessary load to upstream git
>     repositories which host these plugins.
>
>     I believe this particular point is moot when you consider that
>     it is the same for regular source code from git, and that we
>     already have SourceCache as a mitigation for this.

In the case of plugins, having the history seems entirely wasteful and
unnecessary. Why not do shallow clones, fetching only the required
version of the plugin?

> The `venv` plugin origin
> ~~~~~~~~~~~~~~~~~~~~~~~~
[… snip …]
>   * We would not need to bless any specific technique for hosting
>     the plugins, people could have the option to publish plugins
>     on PyPI, or use their preferred VCS so long as `pip` has support
>     for installing from that VCS.

Note that in this case, pip will download the whole VCS history of the
plugin, so if it was a negative for the `git` proposal then it's also a
negative point for this one.

Except for the `git` origin Buildstream can support shallow clones of
plugins, whereas for the ` venv` origin then pip just won't:

    https://github.com/pypa/pip/issues/2432

So the argument that unnecessary VCS history is downloaded for the
plugins is somehow worse for the ` venv` origin.


-- 
Mathieu