1.2.0 image lacks multi-arch manifest

Hey hey team Hashicorp,

Was surprised today to find that — after a couple months using the mutli-arch friendly 1.1.0 image (see related discussion in e.g., #67), the recently published 1.2.0 image only supports amd64. I'm assuming a hiccup/misconfiguration somewhere in the CI pipeline, but haven't been able to track it down.

Using manifest-tool on 1.2.0: (output abridged)

λ manifest-tool inspect consul:1.2.0
Name:   consul:1.2.0 (Type: application/vnd.docker.distribution.manifest.list.v2+json)
Digest: sha256:6293821b092cad164f9d93137297b6e08085ee44a191bf4aa4cf329dda8fc5cd
 * Contains 1 manifest references:
1     Platform:
1           -      OS: linux
1           -    Arch: amd64

Compared to the same command with 1.1.0:

λ manifest-tool inspect consul:1.1.0
Name:   consul:1.1.0 (Type: application/vnd.docker.distribution.manifest.list.v2+json)
Digest: sha256:681fa1f035a7f32310d9133eefec0d0a389f09440831fd6aea818d4c0a461c95
 * Contains 3 manifest references:
1     Platform:
1           -      OS: linux
1           -    Arch: amd64

2     Platform:
2           -      OS: linux
2           -    Arch: arm64
2           - Variant: v8

3     Platform:
3           -      OS: linux
3           -    Arch: 386

So I did some poking around:

This is the only commit to consul in the Docker Hub "official" / library repo since the 1.1.0 release — just bumping the version and commit hash (verified that the hash is correct).
After scanning through @pearkes' PR implementing multi-arch support, my next guess was that perhaps the build script was unable to pull down the necessary binaries for non-amd64 architectures; however, everything looks in order on the Hashicorp releases endpoint for 1.2.0.
Lastly — DockerHub's most recent TravisCI builds suggest the multi-arch config is still being recognized; although I'm not familiar enough with the mechanics of their build setup (bashbrew, etc.) to know where to look next. From the Travis logs:

[...]
Tags: 1.2.0, latest
Architectures: amd64, arm32v6, arm64v8, i386
GitRepo: https://github.com/hashicorp/docker-consul.git
GitCommit: 75d540650a025b682daa8f0760cdce02c5318602
Directory: 0.X
[...]

Any thoughts on this? In the meantime, and if anyone else is looking to upgrade a multiarch deployment, I've built an image compatible with & tested on arm64, armv7, and amd64, which you can pull from jessestuart/consul:1.2.0. Would be nice to sort out this regression, though :) Happy to take a further look if anyone has thoughts on where to investigate apart from the places mentioned above.

hashicorp / docker-consul

1.2.0 image lacks multi-arch manifest #97