In an attempt to tar up the *build* environment for a package to share with a
colleague, I encountered this:

    [env]$ guix pack -m $GUIX_ENVIRONMENT/manifest
    (manifest ...): Wrong number of arguments

From playing around a bit, my guess is that the `<profile>/manifest' files are
just human-readable serializations of <manifest> objects and don't deserialize
back:

    $ guix environment -m ~/.guix-profile/manifest
    (manifest ...): Wrong number of arguments

Asking around on #guix, user leoprikler suggested a workaround by putting this
in a file:

    (call-with-input-file
      "/path/to/manifest"
      (@@ (guix profiles) read-manifest))

and feeding that file to --manifest. This works as intended.

First, am I missing something? Is there a better/preferred way to make use of
the `manifest' files in profiles?

If not, does it seem reasonable to make the `manifest' files automatically
deserialize into the objects they describe? I think this could be a fun, simple
project for a Guix newbie like me, but before I start figuring out how to do
this, I just want to sanity check the idea.

Cheers!