[Haskell-cafe] cannot upgrade stack

[Roger Mason]

Hello,

I'm attempting to upgrade stack on a FreeBSD 11.1 system but it fails:

stack upgrade
Current Stack version: 1.5.1, available download version: 1.7.1
Newer version detected, downloading
Querying for archive location for platform: freebsd-i386-static
Querying for archive location for platform: freebsd-i386
Exception occured when trying to perform binary upgrade:
Unable to find binary Stack archive for platforms: freebsd-i386-static freebsd-i386
Falling back to source upgrade
Selected mirror https://s3.amazonaws.com/hackage.fpcomplete.com/                                 
Downloading timestamp                                                                            
No updates to your package list were found                                                       
Updating package index Hackage (mirrored at https://s3.amazonaws.com/hackage.fpcomplete.com/) ...Could not parse '/tmp/stack-upgrade2294/stack-1.7.1/stack.yaml':
Aeson exception:
Error in $['extra-deps'][0]: failed to parse field 'extra-deps': (Invalid package identifier: "rio-0.1.1.0 at rev:0","rio-0.1.1.0 at rev:0")
See http://docs.haskellstack.org/en/stable/yaml_configuration/

If it matters, I'm using ghc-8.0.2_3.

Thanks for any help,
Roger