Add documentation on how to build CNS

[antonkulaga]

There is an ancient relict that haddock3 depends on called CNS that I understand you, unfortunately, cannot remove yet ( at least according to #82 ).
Building it is a total nightmare as it has a lot of errors after the build, like:

%SETFPEPS increase value of MXFPEPS2 and recompile
 %SETFPEPS error encountered: Could not determine machine epsilon

In haddock2 you had some patches to compile CNS properly, however, there is zero information on how to build CNS for haddock3 master.

[rvhonorato]

however, there is zero information on how to build CNS for haddock3 master.

As we have written in the project's README
WARNING: The main branch is not production-ready

We are still in the process of making sure the modules are doing what they should, once this is done we will move on to prepare the build documentation. 😉

[antonkulaga]

Sorry for the stupid question, but I am trying to find 2.4 version of modified CNS compilation files (to use them to build CNS for haddock 3) but could not locate version 2.4 on github. I filled a website form to get 2.4 distribution because of that.

[amjjbonvin]

2.4 is not freely available from GitHub. You can request it via bonvinlab.org/software

[antonkulaga]

I see. I filled the google form for haddock 2.4 What I really need there is CNS build fixes. Maybe it makes sence to put them somewhere, as asking for permission to use haddock 2.4 in order to recompile CNS in public haddock3 is a bit overkill

[amjjbonvin]

As already explained haddock3 is in heavy development and not yet a production version… better use 2.4 for the time being

[antonkulaga]

better use 2.4 for the time being

Ok, waiting for the access for non-profit distribution of haddock 2.4 then...

[antonkulaga]

Thanks for the download access.
So far I am totally blocked by CNS

%SETFPEPS Machine epsilon determined to be  0.494-323
%SETFPEPS error encountered: Machine epsilon value is too small

I have tried recipes at https://ask.bioexcel.eu/t/cns-errors-before-after-recompilation/54 but nothing worked so far.
My OS is Linux Mint 20.02
UPDATE: after some black magic and whole evening wasted managed to get rid of it (no idea what really worked and what not)..
CNS-stuff is true shamanism

[rvhonorato]

done with #469