[Lmod-users] Prevent module unload from breaking environment

[Alex D. T. <Ale...@vu...>]

Hi lmod-list,

I'm looking into ways to prevent `module unload` from breaking the working environment whenever a dependency of a loaded module is explicitly unloaded.

For instance, assume we have a module X that depends on B; and module B depends on A. Using the depends_on() function to setup those dependencies as shown in the documentation:
https://lmod.readthedocs.io/en/latest/098_dependent_modules.html

Then, the commands:
$ module purge; module load X; module unload B

Result in:
1. unload B
2. unload A
3. print warning that X has unmet dependencies

So the environment is left with a loaded module X that does not work because it is missing A and B. Is there any way to make Lmod avoid ending in such a non-working state?

In this case, I would expect Lmod to do one of the following after executing `module unload B` :
a -- do not unload any module and print error saying that X needs B
b -- unload B and unload X, environment is left with a working module A

If this is a use case never considered before, would it be possible to implement? Should I open an issue in github?

Thanks and kind regards,

Alex Domingo

HPC Team
VUB - Informatie & Communicatietechnologie
Pleinlaan 9 - 1050 Brussel
https://hpc.vub.be