[lsst-dm-stack-users] Working against a common DMstack installation

[Robert Lupton the Good]

I'm not sure that those pages are giving you good advice, but others may disagree.  I personally wouldn't follow advice on any page that uses the word "sandbox".

The first thing to do is to install a central stack, I think you have that.  You can say
	eups list meas_algorithms -v
and find one or more installed versions.  I'm not sure what top-level package you're using (it used to be datarel, or hscPipe for the HSC fork of the stack).

Let's assume that you want to use datarel but a different installed version of obs_lsstSim.  What's available:
> $ eups distrib list obs_lsstSim
> Available products from primary server: http://sw.lsstcorp.org/pkgs
>   obs_lsstSim          generic    4.6.0.1+1
>   obs_lsstSim          generic    4.7.1.0+1
> ...
>   obs_lsstSim          generic    6.2.1.0+2
>   obs_lsstSim          generic    7.1.1.0+1

If you say
	setup datarel
	eups list --setup obs_lsstSim
it'll tell you the default version.  Let's say that's 6.2.1.0+2, but you want 7.1.1.0+1.  So say
	setup --just obs_lsstSim 7.1.1.0+1
and you've overridden the default and you can proceed (why --just?  Because obs_lsstSim knew which products it uses and you don't want them, so just setup obs_lsstSim.  If you do want all its dependencies, omit the --just).

Note that this only lasts as long as your shell is alive.  If you always want to use obs_lsstSim 7.1.1.0+1 the simplest way is to say:
	eups declare --tag heather obs_lsstSim 7.1.1.0+1
(where "heather" is your username --- you can use any name for a tag, but you have to declare it in ~/.eups/startup.py first;  we always allow your username)

Then, next time you start a shell say:
	setup -t heather datarel
and you'll get the default datarel but your version of obs_lsstSim.


OK, what about git?  
	git clone git at git.lsstcorp.org:LSST/DMS/obs_lsstSim
	cd obs_lsstSim
	setup -r . -j
	scons
And you're away.  You can use the --tag trick too:
	eups declare -r . -t heather

					R