Many people have noticed a massive slowdown in the creation of the rubin-env conda environment that is part of what newinstall does to install the LSST Science Pipelines. Much of this is due to the somewhat antiquated dependency solver that conda uses by default.
As of the merge of DM-33305 tonight, newinstall will now use the much faster mamba solver to install the environment. This reduces installation times from hours to minutes.
mamba is also used by the lsstinstall tool (now in beta testing). I apologize for being so focused on the latter tool that I didn’t think of changing newinstall to use mamba as well.
No user impact is expected, aside from faster installation times. If any problems are observed, please let me know or post here.