[mlpack] issue with mlpack Python bindings on Mac OsX

[Ryan Curtin]

On Thu, Dec 27, 2018 at 08:23:33PM +0100, Frodo Jedi wrote:
> Hi Ryan,
> thanks.
> 
> This is the output of cmake .. from a empty build directory:

Perfect... I think this isolates what the problem is:

> -- We will call setup.py install with --prefix=/usr/local --root=

It's a bit strange to call --root= with no option, so I thought this was
the problem.  And then someone else opened an issue on Github with the
same problem, but they were running Linux:

https://github.com/mlpack/mlpack/issues/1621

At this point I realized I could reproduce the issue.  The solution,
then, was to make sure we were calling --root="" when $ENV{DESTDIR} was
empty.

So here is another patched CMakeLists.txt; can you drop it in place,
remove the build directory you were using, and try again?  I think that
this should work...

http://www.ratml.org/misc/CMakeLists.mod2.txt

If it does, I'll open a PR and we'll get the change merged in so it
doesn't happen again.

One other note is, looking at the output you gave, it appears that
mlpack did successfully install, so if you run Python, 'import mlpack'
should work:

> Extracting mlpack-3.0.4-py2.7-macosx-10.12-x86_64.egg to /usr/local/lib/python2.7/site-packages
> Adding mlpack 3.0.4 to easy-install.pth file
> Installed /usr/local/lib/python2.7/site-packages/mlpack-3.0.4-py2.7-macosx-10.12-x86_64.egg

Thanks for the detailed output in this process; that was integral to
getting it figured out (assuming that we got it this time :)).

Ryan

-- 
Ryan Curtin    | "That rug really tied the room together."
ryan at ratml.org |   - The Dude