Standalone build doesn't work about px4-ecl

[julianoes]

Hang on, I might have to read the instructions more carefully.

[julianoes]

No, the Eigen3 path is hard-coded for Mac. A potential fix is in #114.

[mcsauder]

Hi, I had this trouble in another project after upgrading to 16.04 as well. I had to add symbolic links in the following manner:

cd /usr/include/
sudo ln -sf eigen3/Eigen Eigen
sudo ln -sf eigen3/unsupported unsupported

This fixed the issue for me in my other projects this week, (also, I had encountered this issue previously back in Ubuntu 13.04 and 13.10). I hope this might help.

[julianoes]

@mcsauder: thanks for the comment. I prefer not having to do symlinking and using cmake's FindEigen3 to look for it.

See how it's done in #114. Does that work for you?

[mcsauder]

Hi @julianoes,

I agree with your sentiment on avoiding sym links, I only employ them as a last resort. Unfortunately, I already have FIND_PACKAGE(Eigen3) in the top level CMakeLists.txt file for this and two other projects using Eigen that began failing compile after the upgrade to 16.04. :/

As an additional detail that might be worth investigating, if Eigen is installed in the typical manner through apt-get it will install to the ~/usr/include/eigen3 directory, however if you clone Eigen from the source repo and execute a make install, (without altering the default install directory), it will install to your ~/usr/local/include/ directory. On my machine, with Eigen installed to the ~/usr/local/include/eigen3/... directory, my projects will compile without the sym links, however they will not compile without the sym links when Eigen is installed only in the /usr/include/eigen3 directory, even with FIND_PACKAGE(Eigen3) is called out in the top level CMakelists.txt file and even if I have used apt-get to remove Eigen and re-installed it.

At the moment I am contemplating a fresh install of 16.04 to see if it behaves differently than the upgrade from 15.10. I will let you know if I get that accomplished and what results after a clean install. Hopefully a bit of this is some use to you as well.

-Mark

[julianoes]

I think it is common practice to have the package from the distribution in /usr/include and install libraries compiled/downloaded yourself in /usr/local/include. I would also guess that FIND_PACKAGE(Eigen3) should check both paths.

It works fine for me on a fresh 16.04 with libeigen3-dev installed with apt-get.
It shows up like this:

locate eigen3/Eigen/Dense
/usr/include/eigen3/Eigen/Dense

I think you should be able to fix it without re-installing everything.

[mcsauder]

Hi @julianoes,

I just wanted to report back that a new install of Ubuntu 16.04 resolved the issue of not being able to find eigen, so all of my machines are behaving correctly now without symbolic links.

I have no idea what error existed on my machine, but all is well now. Thanks for all of the follow-up and advice!

-Mark

[julianoes]

@mcsauder: nice, thanks for the heads-up!

[priseborough]

So where do we stand with this issue now?

[julianoes]

Yep sorry fixed with #114.