"guix package" failed with "integer expected from stream"

[Konrad Hinsen]

Hi Guix,

Updating my packages after today's "guix pull" fails with the error
message

    guix package: error: integer expected from stream

There are two similar-looking bugs, both closed, suggesting that the
problem has been fixed. I don't understand all the details, but I can
confirm that it's related to substitutes. Disabling substitutes makes
the process go on fine, but I can't really build all my packages myself
in a reasonable length of time.

Should I open a new bug report for this? Or is this problem really fixed
and I just need to do something to profit from the fix?

Cheers,
  Konrad.