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Fermi ScienceTools

This meta-package of the user-facing Fermi ScienceTools employs git submodules to link to component packages. A git submodule is another git repository which is linked to by this repo.

To also fetch these submodules on clone run: git clone --recurse-submodules https://github.com/fermi-lat/ScienceTools.git

If you have cloned the top level repo already you can also grab all the repositories with: git submodule update --init .

Building the tools

The Fermitools has moved to using CMAKE for its build system. When paired with conda for dependency package management this provides robust and well-supported system for cross-compliling the tools on differing host and target systems.

Requirements

With a fully set up conda installation you can install the needed development dependencies for your operating system from the provided conda environment files in environments/.

For example on linux:

conda env create -n fermi-dev -f environments/fermitools-develop-linux.yml
conda activate fermi-dev
Build-only dependencies. System specific environment files also exist for just building the tools, but neither running nor testing them once built.
conda env create -n fermi-build -f environments/fermitools-build-linux-x86.yml
conda activate fermi-build
Generating dependency environment files. A new environment file candidate can be created from the command line. I say candidate because the YAML needs to me modified to actually be installable. You need to remove the 'prefix:' seciton and probably add a '-fermi' to the channel list.
conda env export -n fermi-build --from-history >  environments/fermitools-build.yml

CMake Builds

The build process is split into two steps. Generation is similar to a configure step; The host system is polled for needed attributes, programs, and libraries and a Makefile system is created. The Build stage then executes the generated Makefile system to compile all the Fermitools targets.

Assuming your dependencies are installed and system compilers are all in the local $PATH you can generate a build system by executing the following command from within the ScienceTools directory:

cmake -S . \
-B RelWithDebInfo \
-DCMAKE_BUILD_TYPE=RelWithDebInfo \
-DCMAKE_INSTALL_PREFIX="</install/destination/path>" \
-DCMAKE_PREFIX_PATH="</dependency/search/path/>"

If your CMAKE_INSTALL_PREFIX is the location of your dependencies you can optionally exclude CMAKE_PREFIX_PATH.

This locates needed dependencies and prepares a release build with debug symbols in the 'RelWithDebInfo' directory. To compile the system now run:

cmake --build RelWithDebInfo --parallel

Optionally you can install the tools in your CMAKE_INSTALL_PREFIX with

cmake --build RelWithDebInfo --parallel --target=install

Shell Environment Setup.

The Fermitools relies on a properly setup shell environment to populate needed path information for certain directories. In a conda build this is handled by the activate function, but as a developer working without conda you can instead you the provided scripts/activate.sh. Simply source that file with the argument for your cmake build directory like so:

source scripts/activate.sh RelWithDebInfo

Conda Builds

The sibling repository for this package is https://github.com/fermi-lat/Fermitools-conda

Once checked out it can be used to trigger a conda build with conda build

Tips for Git Submodules

To run a branch and some parallel clone jobs run something like: git clone -b branchname --recurse-submodules -j8 [email protected]:fermi-lat/ScienceTools.git

The metadata for the included submodules is found in the top level .gitmodules file.

The operate on all the submodules as a group, use the git submodule foreach command.

Examples:

  1. Checkout a branch or recover from a detached head: git submodule foreach 'git checkout branchname ||:'
  2. Add a commit: git submodule foreach 'git checkout branchname ||:'
  3. Switch to ssh protocol: git submodule foreach 'git remote -v set-url origin [email protected]:fermi-lat/$(basename $(pwd)).git ||:'
  4. Submodule update alias git config alias.supdate 'submodule update --remote --merge'
  5. Submodule Push alias git config alias.spush 'push --recurse-submodules=on-demand'