`gzip` missing from singularity base image

[matthdsm]

Hi,

Would it be possible to add gzip by default to the singularity base image?
nf-core is migrating to wave containers where possible, but CI tests using the common echo "" | gzip > test.gz pattern for stub tests fail using the generated singularity images, since gzip is not available.

I'm aware it's possible to add gzip as a dependency to each module as they are updated, but I think it would be cleaner to just add it to the base image as a common utility, so the singularity images are on par with the docker ones

Thanks
Matthias

[pditommaso]

Have you considered using basePackages setting e.g.

wave.build.conda.basePackages = 'conda-forge::procps-ng conda-forge::gzip`

https://docs.seqera.io/nextflow/reference/config/wave#wavebuildcondabasepackages

[matthdsm]

Great idea, wasn't aware of the option.
nf-core/tools#4449