installation-name for snapshot builds

[Alexander D. Knauth]

Right now, the default installation-name for all snapshot builds is “snapshot”, which means that if I have multiple snapshots installed, then the user package scopes for the different snapshot installations are the same.

Should that be changed so that the installation-name is different for different snapshots?

The part that would need to change is here, I think:
https://github.com/racket/distro-build/blob/master/distro-build-server/drive-clients.rkt#L258

[Matthew Flatt]

At Fri, 6 Mar 2015 14:21:26 -0500, "Alexander D. Knauth" wrote:
> Right now, the default installation-name for all snapshot builds is
> “snapshot”,

The intent behind that choice is to make it easy to replace a snapshot
with a newer one without reinstalling packages from scratch.

More generally, we have three different kinds of defaults for three
kinds of builds:

* `make` from a Git repo checkout
- the default installation name is "installation"
- the default package scope is installation

The idea here is that everything should stay with the build.

* a snapshot
- the default installation name is "snapshot"
- the default package scope is user

The idea here is that a user likely wants to discard a snapshot and
replace it with another, so packages are in user scope but with the
same name.

* a release
- the default installation name is the version
- the default package scope is user

The idea here is that installing multiple releases should work by
default, and packages should be in user scope for permission
reasons.

It's not obvious that the defaults are right for the different modes,
but I think they have worked well so far.

> which means that if I have multiple snapshots installed, then the
> user package scopes for the different snapshot installations are the same.

That's true, but you can give any installation a different name with

racket pkg config -i --set installation-name <new-name>