NGsolve stable and nightlies won't work for us. Let's try to solve the dependency/Debian packaging hell ourselves

[Kunda1]

Per the ngsolve/netgen forum

Starting with release 6.2.1711 Ubuntu packages are now hosted on Launchpad.

Stable: https://launchpad.net/~ngsolve/+archive/ubuntu/ngsolve
Nightly: https://launchpad.net/~ngsolve/+archive/ubuntu/nightly

EDIT: NGsolve is not the same as Netgen. It depends on oce which is a deal breaker.

[triplus]

Good to hear that.

P.S: Will likely help us when it comes to FreeCAD PPA/AppImage effort.

[looo]

does ngsolve include netgen?

[Kunda1]

does ngsolve include netgen?

If you look in the ngsolve repo, you'll see it uses netgen as a submodule.

[triplus]

I see this PPA is more about NGSolve and less about Netgen. In addition currently it looks like there might be some package conflicts as they use liboce and we use OCC from PPA. And there seems to be some clash involved when trying to install NGSolve.

Anyway at least it's a start. And who knows maybe there will be an official Netgen related PPA in the future. In addition if they officially provide NGSolve on PPA likely more experience on their side in this area will result in better general Netgen support on Linux in the future.

[sgrogan]

I see this PPA is more about NGSolve and less about Netgen.

It seems the project is geared towards building everything. NGSolve depends on Netgen which depends on nglib. nglib and the netgen-headers are all that we need for FreeCAD (actually just libnglib.so unless you are compiling and linking FreeCAD to nglib)

n addition currently it looks like there might be some package conflicts as they use liboce and we use OCC from PPA.

This is definitely a problem so this package won't work with the PPA. Also netgen sources need to be patched to use OCCT 7.x.

And there seems to be some clash involved when trying to install NGSolve.

Do you have a newer oce installed, perhaps from the FreeCAD-stable PPA? The NGSolve package uses the default distro oce.

[triplus]

Likely they will need to sort out some install dependency first. As the package tries to install oce -dev packages. And such packages are usually only needed for building the package.

P.S. But then again i didn't investigate in-depth for now. And it could be something else related to my system.

[sgrogan]

As the package tries to install oce -dev packages

I noticed that NGSolve lists several dev packages and g++ and gcc as run time depends. Maybe the solver compiles some stuff on the fly at runtime? I think Fenics does this as well but it has it's own compiler.

[looo]

As far as I remember, we can not use netgen6.2 directly. Basically there is one change of the newer netgen where I didn't find a easy solution on our side. For the conda netgen-package I use a modified netgen source. Basically it's this line which needs some more effort to get solved for smesh in FreeCAD.

[sgrogan]

For the conda netgen-package I use a modified netgen source

Do you build NGSolve or NetGen or just nglib? The problem seems to be NetGen is going for one big package and FreeCAD only uses a small fraction of the package. We only need libngen-dev and the netgen-headers. This is leading to dependency bloat. If we provide a ppa for what FreeCAD needs, we need to provide the full bloated package for users that use NetGen for something else. FreeCAD can't really use any of the stuff in the newer Netgen versions because supporting it cross platform with whatever oce/occt version that platform is using.

This is getting more like SMESH/SALOME. I know we are trying to move stuff out of 3rd party and it's a nightmare for the developers to maintain, but as a packager netgen is a PITA.

EDIT: I probably should have put this whole post in [rant][rant] tags, but it is extremely frustrating.