Installation with lsstsw and lsst-build¶

This page will guide you through installing the LSST Science Pipelines from source with lsstsw and lsst-build. These are the same tools LSST Data Management uses to build and test the Science Pipelines.

Since lsstsw presents the Science Pipelines as a directory of Git repositories clone from github.com/lsst, this installation method can be very convenient for developing Science Pipelines code.

Science Pipelines developers should also consult the DM Developer Guide, and the Workflow page in particular.

If you have difficulty installing LSST software:

review the known installation issues for your platform.
reach out on the Support forum at community.lsst.org.

1. Prerequisites¶

Before you begin:

Install and configure Git LFS for LSST DM’s data servers.
Install prerequisites for your platform: macOS, Debian / Ubuntu, or Centos / RedHat.
If you opt not to use lsstsw ’s default Python environment you need to install these Python dependencies.

2. Deploy lsstsw¶

Begin by choosing a working directory, then deploy lsstsw into it:

git clone https://github.com/lsst/lsstsw.git
cd lsstsw
./bin/deploy
source bin/setup.sh

For more information about the deploy command, such as using Python 2.7 instead of 3, see About the lsstsw deploy script.

3. Build the Science Pipelines packages¶

From the lsstsw directory, run:

rebuild lsst_distrib

Once the rebuild step finishes, note the build number printed on screen. It is formatted as “bNNNN.” Tag this build as current so that EUPS can set it up by default:

eups tags --clone bNNNN current

Finally, set up the packages with EUPS:

setup lsst_distrib

See Setting up installed LSST Science Pipelines for more information.

4. Testing Your installation (optional)¶

Once the LSST Science Pipelines are installed, you can verify that it works by running a demo project. This demo processes a small amount of SDSS data.

Sourcing the Pipelines in a new shell¶

In every new shell session you will need to set up the Science Pipelines environment and EUPS package stack.

Run these two steps:

Activate the lsstsw software environment by sourcing the setup.sh script in lsstsw’s bin directory:
```
source bin/setup.sh
```
If you are running in a csh or tcsh, run this set up script instead:
```
source bin/setup.csh
```
Set up a top-level package:
```
setup lsst_distrib
```
Instead of lsst_distrib, you can set up a different top-level package like lsst_apps or any individual EUPS package. See Top-level packages to install.

About the lsstsw deploy script¶

The deploy script automates several things to prepare an LSST development environment:

Installs Git.
Installs Git LFS (you are still responsible for configuring it).
Installs a Miniconda Python environment specific to this lsstsw workspace. The default Python is Python 3, but you can switch to Python 2.7 if necessary. See How to use Python 2.7.
Installs EUPS into eups/current/.
Clones lsst-build, which runs the build process.
Clones versiondb, a robot-managed Git repository of package dependency information.
Creates an empty stack installation directory, stack/.

This environment, including the EUPS, Miniconda, Git, and Git LFS software, is only activated when you source the bin/setup.sh or bin/setup.csh scripts in a shell. Otherwise, lsstsw does not affect the software installed on your computer.

How to use Python 2.7¶

The lsstsw deploy script installs Miniconda as self-contained Python environment. By default, deploy installs a Python 3 version of Miniconda. For testing Python 2.7 compatibility, you can create an lsstsw deployment with a Python 2.7 version of Miniconda using the deploy -2 argument:

./bin/deploy -2

About the lsstsw rebuild command¶

The rebuild command accomplishes the following:

Clones all Science Pipelines packages from github.com/lsst. rebuild
Runs the Scons-based build process to compile C++, make Pybind11 bindings, and ultimately create the lsst Python package. The stack is built and installed into the stack/ directory inside your lsstsw/ work directory.

lsstsw clones repositories using HTTPS (see repos.yaml. Our guide to Setting up a Git credential helper will allow you to push new commits up to GitHub without repeatedly entering your GitHub credentials.

Building from branches¶

lsstsw’s rebuild enables you to clone and build development branches.

To build lsst_distrb, but use the Git branch my-feature when it’s available in a package’s repository:

rebuild -r my-feature lsst_distrib

Multiple ticket branches across multiple products can be built in order of priority:

rebuild -r feature-1 -r feature-2 lsst_distrib

In this example, a feature-1 branch will be used in any package’s Git repository. A feature-2 branch will be used secondarily in repositories where feature-1 doesn’t exist. Finally, lsstsw falls back to using the master branch for repositories that lack both feature-1 and feature-2.

lsstsw deploy command reference¶

usage: deploy.sh [-2|-3] [-b] [-h]

-2¶: Install a Python 2-based Miniconda.

-3¶: Use a Python 3-based Miniconda (default).

-b¶: Use bleeding-edge conda packages.

-h¶: Print the help message.

lsstsw rebuild command reference¶

rebuild [-p] [-n] [-u] [-r <ref> [-r <ref2> [...]]] [-t <eupstag>] [product1 [product2 [...]]]

-p¶: Prep only.

-n¶: Do not run git fetch in already-downloaded repositories.

-u¶: Update the repos.yaml package index to the master branch on GitHub of https://github.com/lsst/repos.

-r <git ref>¶: Rebuild using the Git ref. A Git ref can be a branch name, tag, or commit SHA. Multiple -r arguments can be given, in order or priority.

-t¶: EUPS tag.