JuJu does not appear to support --constraints arch=arm64

$ apt-cache policy juju-core
juju-core:
  Installed: 1.20.5-0ubuntu1~14.04.1~juju1

We have started to enable arm64 nodes on a MaaS 1.6 server and now attempting to utilize them with juju. It appears that the latest stable build of juju does not understand " --constraints arch=arm64" when trying to bootstrap a MaaS environment

We have temporarily resolved the constraints problem by using a custom hacked version of juju 1.18.1.

 Candidate: 1.20.5-0ubuntu1~14.04.1~juju1
  Version table:
 *** 1.20.5-0ubuntu1~14.04.1~juju1 0
        500 http://ppa.launchpad.net/juju/stable/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status
     1.19.4-0ubuntu1~14.04.1~juju1 0
        500 http://ppa.launchpad.net/juju/devel/ubuntu/ trusty/main amd64 Packages
     1.18.1-0ubuntu1 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages

sfeole@ubuntu-feole:~$ juju bootstrap --debug --constraints arch=arm64
2014-08-28 23:21:41 INFO juju.cmd supercommand.go:37 running juju [1.20.5-trusty-amd64 gc]
2014-08-28 23:21:41 DEBUG juju.environs.configstore disk.go:69 Making /home/sfeole/.juju/environments
2014-08-28 23:21:41 DEBUG juju.provider.maas environprovider.go:30 opening environment "maas".
2014-08-28 23:21:41 DEBUG juju.environs.simplestreams simplestreams.go:389 fetchData failed for "images/streams/v1/index.sjson": file 'ec7a36bd-5783-4f86-88a9-9e4592ee3db1-images/streams/v1/index.sjson' not found not found
2014-08-28 23:21:41 DEBUG juju.environs.simplestreams simplestreams.go:363 cannot load index "streams/v1/index.sjson": invalid URL "images/streams/v1/index.sjson" not found
2014-08-28 23:21:42 DEBUG juju.environs.simplestreams simplestreams.go:389 fetchData failed for "images/streams/v1/index.json": file 'ec7a36bd-5783-4f86-88a9-9e4592ee3db1-images/streams/v1/index.json' not found not found
2014-08-28 23:21:42 DEBUG juju.environs.simplestreams simplestreams.go:363 cannot load index "streams/v1/index.json": invalid URL "images/streams/v1/index.json" not found
2014-08-28 23:21:42 INFO juju.utils http.go:59 hostname SSL verification enabled
2014-08-28 23:21:42 INFO juju.utils http.go:59 hostname SSL verification enabled
2014-08-28 23:21:42 DEBUG juju.environs.simplestreams simplestreams.go:389 fetchData failed for "http://cloud-images.ubuntu.com/releases/streams/v1/mirrors.sjson": cannot find URL "http://cloud-images.ubuntu.com/releases/streams/v1/mirrors.sjson" not found
2014-08-28 23:21:42 DEBUG juju.environs.simplestreams simplestreams.go:466 no mirror index file found
2014-08-28 23:21:42 DEBUG juju.environs.simplestreams simplestreams.go:367 read metadata index at "http://cloud-images.ubuntu.com/releases/streams/v1/index.sjson"
2014-08-28 23:21:42 DEBUG juju.environs.simplestreams simplestreams.go:534 candidate matches for products ["com.ubuntu.cloud:server:12.04:amd64" "com.ubuntu.cloud:server:12.04:i386" "com.ubuntu.cloud:server:12.04:armhf" "com.ubuntu.cloud:server:12.04:arm64" "com.ubuntu.cloud:server:12.04:ppc64el" "com.ubuntu.cloud:server:12.10:amd64" "com.ubuntu.cloud:server:12.10:i386" "com.ubuntu.cloud:server:12.10:armhf" "com.ubuntu.cloud:server:12.10:arm64" "com.ubuntu.cloud:server:12.10:ppc64el" "com.ubuntu.cloud:server:13.04:amd64" "com.ubuntu.cloud:server:13.04:i386" "com.ubuntu.cloud:server:13.04:armhf" "com.ubuntu.cloud:server:13.04:arm64" "com.ubuntu.cloud:server:13.04:ppc64el" "com.ubuntu.cloud:server:13.10:amd64" "com.ubuntu.cloud:server:13.10:i386" "com.ubuntu.cloud:server:13.10:armhf" "com.ubuntu.cloud:server:13.10:arm64" "com.ubuntu.cloud:server:13.10:ppc64el" "com.ubuntu.cloud:server:14.04:amd64" "com.ubuntu.cloud:server:14.04:i386" "com.ubuntu.cloud:server:14.04:armhf" "com.ubuntu.cloud:server:14.04:arm64" "com.ubuntu.cloud:server:14.04:ppc64el" "com.ubuntu.cloud:server:14.10:amd64" "com.ubuntu.cloud:server:14.10:i386" "com.ubuntu.cloud:server:14.10:armhf" "com.ubuntu.cloud:server:14.10:arm64" "com.ubuntu.cloud:server:14.10:ppc64el"] are [{Tue, 08 Jul 2014 15:49:14 +0000 products:1.0 image-ids joyent [{eu-ams-1 https://eu-ams-1.api.joyentcloud.com} {us-sw-1 https://us-sw-1.api.joyentcloud.com} {us-east-1 https://us-east-1.api.joyentcloud.com} {us-west-1 https://us-west-1.api.joyentcloud.com}] streams/v1/com.ubuntu.cloud:released:joyent.sjson [com.ubuntu.cloud:server:13.10:amd64 com.ubuntu.cloud:server:12.04:amd64 com.ubuntu.cloud:server:14.04:amd64]} {Thu, 28 Aug 2014 16:25:45 +0000 products:1.0 image-ids aws [{us-east-1 https://ec2.us-east-1.amazonaws.com} {ap-northeast-1 https://ec2.ap-northeast-1.amazonaws.com} {eu-west-1 https://ec2.eu-west-1.amazonaws.com} {ap-southeast-1 https://ec2.ap-southeast-1.amazonaws.com} {ap-southeast-2 https://ec2.ap-southeast-2.amazonaws.com} {us-west-2 https://ec2.us-west-2.amazonaws.com} {us-west-1 https://ec2.us-west-1.amazonaws.com} {sa-east-1 https://ec2.sa-east-1.amazonaws.com}] streams/v1/com.ubuntu.cloud:released:aws.sjson [com.ubuntu.cloud:server:13.10:amd64 com.ubuntu.cloud:server:13.04:amd64 com.ubuntu.cloud:server:12.10:i386 com.ubuntu.cloud:server:12.04:i386 com.ubuntu.cloud:server:14.04:i386 com.ubuntu.cloud:server:13.10:i386 com.ubuntu.cloud:server:10.04:amd64 com.ubuntu.cloud:server:10.04:i386 com.ubuntu.cloud:server:14.04:amd64 com.ubuntu.cloud:server:12.10:amd64 com.ubuntu.cloud:server:13.04:i386 com.ubuntu.cloud:server:11.10:amd64 com.ubuntu.cloud:server:12.04:amd64 com.ubuntu.cloud:server:11.10:i386 com.ubuntu.cloud:server:14.10:amd64 com.ubuntu.cloud:server:14.10:i386]} {Thu, 28 Aug 2014 06:58:50 +0000 products:1.0 image-ids brightbox [{gb1 https://api.gb1.brightbox.com}] streams/v1/com.brightbox:official.sjson [com.ubuntu.cloud:server:12.04:amd64 com.ubuntu.cloud:server:14.04:amd64 com.ubuntu.cloud:server:12.04:i386 com.ubuntu.cloud:server:14.04:i386]} {Fri, 08 Aug 2014 01:46:47 +0000 products:1.0 image-ids hpcloud [{region-b.geo-1 https://region-b.geo-1.identity.hpcloudsvc.com:35357/v2.0/} {region-a.geo-1 https://region-a.geo-1.identity.hpcloudsvc.com:35357/v2.0/}] streams/v1/com.ubuntu.cloud:released:hpcloud.sjson [com.ubuntu.cloud:server:12.04:amd64 com.ubuntu.cloud:server:13.10:amd64 com.ubuntu.cloud:server:14.04:amd64 com.ubuntu.cloud:server:12.10:amd64]} {Thu, 28 Aug 2014 16:05:36 +0000 products:1.0 image-ids azure [{Japan West https://management.core.windows.net/} {West Europe https://management.core.windows.net/} {East US 2 https://management.core.windows.net/} {Southeast Asia https://management.core.windows.net/} {South Central US https://management.core.windows.net/} {Australia Southeast https://management.core.windows.net/} {Australia East https://management.core.windows.net/} {East Asia https://management.core.windows.net/} {East US https://management.core.windows.net/} {Central US https://management.core.windows.net/} {West US https://management.core.windows.net/} {North Europe https://management.core.windows.net/} {North Central US https://management.core.windows.net/} {Japan East https://management.core.windows.net/} {China East https://management.core.chinacloudapi.cn/} {China North https://management.core.chinacloudapi.cn/} {Brazil South https://management.core.windows.net/}] streams/v1/com.ubuntu.cloud:released:azure.sjson [com.ubuntu.cloud:server:12.04:amd64 com.ubuntu.cloud:server:14.04:amd64 com.ubuntu.cloud:server:12.10:amd64 com.ubuntu.cloud:server:14.10:amd64]} {Thu, 28 Aug 2014 16:12:26 +0000 products:1.0 image-ids aws-govcloud [{us-gov-west-1 https://ec2.us-gov-west-1.amazonaws-govcloud.com}] streams/v1/com.ubuntu.cloud:released:aws-govcloud.sjson [com.ubuntu.cloud:server:13.10:amd64 com.ubuntu.cloud:server:12.04:i386 com.ubuntu.cloud:server:14.04:i386 com.ubuntu.cloud:server:13.10:i386 com.ubuntu.cloud:server:10.04:amd64 com.ubuntu.cloud:server:14.04:amd64 com.ubuntu.cloud:server:10.04:i386 com.ubuntu.cloud:server:12.04:amd64]} {Sat, 26 Jul 2014 01:44:05 +0000 products:1.0 image-ids aws-cn [{cn-north-1 https://ec2.cn-north-1.amazonaws-cn.com.cn}] streams/v1/com.ubuntu.cloud:released:aws-cn.sjson [com.ubuntu.cloud:server:13.10:amd64 com.ubuntu.cloud:server:12.04:i386 com.ubuntu.cloud:server:14.04:i386 com.ubuntu.cloud:server:13.10:i386 com.ubuntu.cloud:server:14.04:amd64 com.ubuntu.cloud:server:12.04:amd64]}]
2014-08-28 23:21:42 DEBUG juju.environs.simplestreams simplestreams.go:847 finding products at path "streams/v1/com.ubuntu.cloud:released:joyent.sjson"
2014-08-28 23:21:42 INFO juju.utils http.go:59 hostname SSL verification enabled
2014-08-28 23:21:42 DEBUG juju.environs.simplestreams simplestreams.go:885 metadata: &{map[com.ubuntu.cloud:server:13.10:amd64:{saucy 13.10 amd64 map[20140227:0xc21017d9c0 20140608:0xc21017dae0 20140519:0xc21017dba0 20140410:0xc21017dc60]} com.ubuntu.cloud:server:12.04:amd64:{precise 12.04 amd64 map[20140408:0xc21017dd80 20140227:0xc21017de40 20140608:0xc21017df00 20140519:0xc210107000]} com.ubuntu.cloud:server:14.04:amd64:{trusty 14.04 amd64 map[20140416:0xc210107120 20140519:0xc2101071e0 20140608:0xc2101072a0]}] map[crsn:map[euww1:map[region:eu-ams-1 endpoint:https://eu-ams-1.api.joyentcloud.com] ussw1:map[region:us-sw-1 endpoint:https://us-sw-1.api.joyentcloud.com] usww1:map[region:us-west-1 endpoint:https://us-west-1.api.joyentcloud.com] usee1:map[region:us-east-1 endpoint:https://us-east-1.api.joyentcloud.com]]] Tue, 08 Jul 2014 15:49:14 +0000 products:1.0 com.ubuntu.cloud:released:joyent }
2014-08-28 23:21:42 INFO juju.cmd cmd.go:113 Bootstrap failed, destroying environment
2014-08-28 23:21:42 INFO juju.provider.common destroy.go:15 destroying environment "maas"
2014-08-28 23:21:42 ERROR juju.cmd supercommand.go:323 invalid constraint value: arch=arm64
valid values are: [amd64]