Comment 2 for bug 1261452

juju-core also depend on golang of course, which is also not available for arm64.

Here is the status as of 2012-12-17 as I understand it:

1) Go
   a) there is a version of gccgo in trusty that can compile juju, but only with a patched version of the 'go tool'
      i) need kick these patches upstream (they are in review)
      ii) need a plan to provide a gccgo-compiled go tool in trusty
   b) there is a problem with setting up the heap for statically linked gccgo-compiled binaries
      i) need to beat some feedback out of golang-dev about this
      ii) we can provide a patch for this for trusty regardless of what upstream does

2) mongodb
   a) the v8 thing
      i) it is possible a v8 port to arm64 will appear, although it's not clear that this will suffice for mongodb
      ii) mongodb can be built without js support though, and we think juju will work with such a mongodb (need to check this!)
   b) even without v8, some porting is required
      i) intel assembly can be replaced with gcc intrinsics (Robie has patches for this and is planning on sending them upstream)
      ii) there appears to be a toolchain bug in trusty (I've been pointed to a fix upstream and will be testing that out as soon as I finish typing this comment!)