Hi Mette,
A few possible solutions:
1 (easiest, probably slow). Just install the following binary into your environment
The reason this may be slow is that dependencies are built in a very non-optimized way for complex reasons.
2 (still easy). Install all the dependencies (megahit, samtools, bwa) separately and then install
This is, in fact, how the conda package works
3 (not so easy, probably the most dockery way). Install all the dependencies. Add haskellstack and build NGLess from scratch
4 (no idea, I'm not that fluent in docker). Use this prebuilt docker image and add your things?
HTH