Convert Shell Conduit Pipeline to Regular Conduit Process

[ProofOfKeags]

Currently the only way to wire up conduits to the output of shell processes is

shell "blah" $| conduit myConduitPipeline and it requires that myConduitPipeline both inputs and outputs bytestrings.

What I would like to be able to do is to wire up a bunch of shell processes and then use that composite process as a regular conduit source with an output of ByteString such that I can wire up downstream processes without being constrained to have the downstream process result in ByteString outputs. This necessarily loses the ability to wire it up into the inputs of other shell processes but I think this is a common enough use case to be useful.