Update ACE package

[paskino]

Reflects updates done on ACE.
Uses Gadgetron version that compiles with GPU support.

[KrisThielemans]

seems good to me. Feel free to merge, but send email that you're updating the Gadgetron version.

but why the branch name?

[paskino]

SCARF is the STFC cluster, that's the origin of the name of this PR.

About the Gadgetron repo change:

1. the Gadgetron version we currently have in master is from 24/11/2017.
2. Gadgetron wouldn't build with GPU support. I patched it (the Gadgetron version we have in the Superbuild) and submitted a PR to Gadgetron.
3. Gadgetron merged my PR on 28/7/2018
4. So this patch is needed to have GPU support. It is linked to the same 24/11/2017 gadgetron version as before, but the repository is the CCPPETMR/gadgetron fork.

[KrisThielemans]

I'm somewhat reluctant to point to our own gadgetron fork, as it gives the impression we're deviating from them. I vote for pointing to the main gadgetron repo somewhere after acceptance of your PR. @DANAJK , @ckolbPTB @johannesmayer any suggestions/opinions?

[DANAJK]

Similar to #134 , I have no objection to pointing to a Gadgetron commit that works for us. Hopefully more recent that one year though.

[paskino]

I tried to build Gadgetron after the PR was merged and it fails.
I had a first error coming from the CXX flag -Werror=terminate which isn't recognised.

Fixed that (requires changing Gadgetron CMakeLists.txt) and I got to

/home/sirfuser/devel/buildgadgetron/sources/Gadgetron/toolboxes/mri_core/mri_core_data.h:5:30: fatal error: ismrmrd/waveform.h: No such file or directory
compilation terminated.

[DANAJK]

waveforms are something that is being added to ISMRMRD (to support ECG information as an example).
Maybe you need to update ISMRMRD too?

[KrisThielemans]

we should follow the same strategy for ISMRMRD as in #134 I think: occasional updates, with testing first. if we need ECG (or any other schanges in ISMRMRD) now or not I have no idea. As long as it doesn't break things, it's fine for me of course.

[KrisThielemans]

ah sorry. I hadn't seen Edo's error. Seems Gadgetron doesn't check the ISMRMRD version properly then...

Then it needs updating ISMRMRD of course.

[paskino]

I'll see if I find a couple of Gadgetron/ISMRMRD which work for us.
The -Werror=terminate problem might mean that there is a minimum requirement on gcc version, and the one we have isn't sufficient.

[KrisThielemans]

I guess do a git blame to find out when they introduced that option. Not nice if it isn't guarded by appropriate checks on compiler.

[paskino]

OK, the new Gadgetron/master requires at least GCC version 6.

Ubuntu 16.04 has 5.4. On the VM it could be possible to install gcc version 6 following this link

I see a few options:

1. Build a new VM with Ubuntu 18.04 which ships GCC 7.3.0
2. Add the new unofficial repository to get GCC 6 onto the current VM (Ubuntu 16.04)
3. Use conda
4. Keep outdated Gadgetron in the short term.

Although option 3 is still in a work-in-progress phase I strongly believe that we should pursue that direction.

[paskino]

They introduced a check of the availability of -Werror=terminate (which I incidentally couldn't find documented anywhere) in the latest Gadgetron master branch. But along with that, they check minimum version of GCC >= 6.

[KrisThielemans]

This discussion isn't really about this PR. I've created a new Issue for it: #146

This PR does 2 things: change ACE stuff, and change Gadgetron Tag. Those are independent, and the Gadgetron stuff is preventing us merging the ACE changes.

@paskino, please revert Gadgetron changes, change the title of the PR, and then squash-merge.