Updating ldmx-sw

This page is helpful for those coming back to ldmx-sw and wishing to update there local copy of it. It can also be a helpful guide for anyone interesting in debugging ldmx-sw since often it is helpful to start with the most recent ldmx-sw.

We can update ldmx-sw through three main stages. These stages are not necessarily connected (i.e. you could update the code and re-build without changing the environment if desired).

Update Environment

The ldmx command includes a method for updating the environment on your machine.

ldmx pull dev latest

The pull command informs ldmx to download the latest image no matter what (The more common use command will only spend time downloading if the image is not available.)

The latest tag is one tag that evolves with the image as new versions are built. If you wish to avoid accidentally upgrading your environment, you are encouraged to use specific versions of the image (e.g. ldmx use dev 4.2.0).

Update Source Code

Updating the source code of ldmx-sw mostly amounts to using various git comands to download the updates other developers have uploaded to GitHub.

First, we switch to the main branch of ldmx-sw trunk. Even if you are on a different branch, it will be best to first update your local trunk before trying to update your different branch.

git switch trunk

Now pull down the updates from GitHub.

git pull origin trunk

Finally, make sure any submodules that were updated or newly introduced are also updated along with the change in source code.

git submodule update --init --recursive

git config submodule.recurse true

If you are on a different branch (and want to carry your changes with you), you can now go back to that branch and re-apply your updates on top of the new trunk. This process is called "rebasing" and can lead to conflicts if the files you changed are the same as ones changed on trunk. For small changes or additions (e.g. adding a new processor for an analysis), this can be done with ease and it will make comparing your developments to what is on trunk easier.

git switch my-branch
git rebase trunk

Fully Clean Re-Build

Cleaning the source tree is necessary to remove any files generated during the building process. The programs we use to configure (CMake) and build (make) our software do a pretty good job of automatically re-building files if the source files change, but we have some custom configuration that does not follow this protocol and sometimes leads to errors. To avoid these errors, it is helpful to remove all generated files and start a new build "clean" (or from scratch). The following git commands remove all files that are not being tracked by git (and thus we assume are generated files).

git clean -xfd
git submodule foreach --recursive git clean -xfd

If you want to persist some files that are within the ldmx-sw directory and are not being tracked by git (for example, some data files), then you will need to at minimum delete the build and install directories and clean out the generated files from the Framework directory.

rm -r build install
git -C Framework clean -xfd

rm -r build install

The final build and install steps are similar to the past ones. Just note that they will take longer since the build is starting from scratch.

ldmx cmake -B build -S .
ldmx cmake --build build --target install