I don't think it's about effort to set up EasyBuild (although we do have a hard requirement for a modules tool).
Spack is perhaps more attractive to software developers because it has specific features for that use, like the flexible dependency handling mechanism and the concretiser.
In my view, EasyBuild is better suited than Spack to maintain a central software stack, but I'm definitely biased. :)
Not all of this is 100% correct, so let me pitch in:
- EasyBuild currently doesn't have an uninstall option, that's true, but since every software installation sits in its own separate directory, it basically boils down to removing that directory + the environment module file that EasyBuild generated for it;
- EasyBuild can install "binary packages" (see the 'Binary' easyblock). Examples are the Intel compilers, CUDA, etc. We don't provides pre-built binaries for software that EasyBuild installs from source though, that's true;
- EasyBuild has no "environments" concept. The closest thing perhaps is the 'Bundle' easyblock, that can be used to "glue" different environment modules together. We mostly rely on the environment modules tool (Lmod) so this, see for example module collections: https://lmod.readthedocs.io/en/latest/010_user.html#user-col...
- EasyBuild does indeed require an environment modules tool. Both Lmod (Lua-based) and Environment Modules (Tcl-based) are supported;
- EasyBuild also supports RPATH linking (see https://docs.easybuild.io/rpath-support/), but it's not the default.
> "EB is really set up to automate a certain type of installation common in HPC"
EasyBuild is definitely geared towards installing software on HPC systems, but there's no "certain type of installation common in HPC": we support software using a wide variety of installation procedures. But maybe you're referring to installing software in a shared filesystem (NFS, usually something like /apps).
> it basically boils down to removing that directory + the environment module file that EasyBuild generated for it
Another important thing is knowing what depends on that package (so you don't remove something else's dependency). This is something that EB doesn't track after installation time.
> EasyBuild can install "binary packages"
What I meant here is that EB has no binary packaging system of its own. It has no binary package format, no signing, no way to take an installation and bundle it up into a file that can be installed (potentially in a different location) on another system. Spack, Nix, and Guix all have systems for creating and (re)installing binary substitutes for source builds (we call them build caches). EB can install someone else's binary package/distribution (we can too FWIW), but it can't create its own.
> But maybe you're referring to installing software in a shared filesystem (NFS, usually something like /apps).
Yes -- specifically that, with environment modules. Spack installations similarly all go in their own directories, but you can compose them in many different ways with environments and views. e.g., you can:
- Create a symlink tree of many packages together in a common prefix (a view)
- "project" package installations into different directory layouts with symlinks, hardlinks, or relocated copies
And you don't have to load packages one by one with modules. You can avoid modules entirely with `spack load` or use `spack env activate` to put everything in an env into your `PATH` (and other env vars).
