I think this is quite an ambitious plan, and unlikely we will manage to have it completed by March 31st.

I suggest we just try to move third party libraries out of the science pipeline stack, to start.

From our conversations in slack, in order to do that, we need to include conda compilers in the environment and ensure that the rebuild of lsst_distrib is working.

I think this is already a big change, and probably should be documented in a different Jira issue.

builds of lsst_distrib on OS X and centos 7 with conda compilers are working well - I also did a deploy+build on a raw centos 7 container with only git installed - I had to add `patch` to get the eups eigen to build

To get this in jenkins, I need to either modify sconsUtils to be smarter about auto-selecting conda compilers if available, or explicitly set `SCONSUTILS_USE_CONDA_COMPILERS=1` somewhere

this script should work on any system:

git clone https://github.com/lsst/lsstsw.git

cd lsstsw

./bin/deploy -r tickets/DM-23835

source bin/setup.sh

export SCONSUTILS_USE_CONDA_COMPILERS=1

. /lsstsw/bin/envconfig -n lsst-scipipe-tickets-DM-23835.726a682

# conda install patch (necessary on bare centos7 docker image)

rebuild -r tickets/DM-23835 lsst_distrib

Note: this ticket's branches do have a few patched unit tests to make this work properly which will go away once we fix capitalization

There is a current build (https://ci.lsst.codes/blue/organizations/jenkins/stack-os-matrix/detail/stack-os-matrix/31686/pipeline/47) which I expect to pass, as ci_hsc_gen2 and ci_hsc_gen3 have passed on different executors.

That build is running to verify some fixes that were merged into cfitiso this morning on conda-forge which caused a segfault in ci_hsc_gen2 on linux (but not on mac).

That build does not include sconsUtils changes. I have a new sconsUtils build running to verify some changes for the open pull requests:
https://ci.lsst.codes/job/stack-os-matrix/31693/

I believe these two builds should resolve any last issues in the code preventing merging, but I can execute one final ci_hsc build after the sconsUtils changes are verified.

The scipipe_conda_env PR has been reviewed and approved.

The sconsUtils PR has been reviewed by Tim Jenness and I think it's ready for merge.\

All other repos, except for psfex, have changes to their eups table files or .cfg -in almost all cases just removing the eups third parties, supporting the new third parties. Gabriele Comoretto [X] if you wouldn't mind looking at that. I will post a list of those repos.

The psfex changes are an update to the autotools configurations, based on upstream psfex changes and this conda-forge patch, to more easily compile against the conda-forge provided libraries and headers. This is the reason for the lapack inclusion in the bleed file.

the build mentioned above https://ci.lsst.codes/job/stack-os-matrix/31693/ has failed. Did a new one succeed?

I have reviewed the PRs as requested.