So I'm working on building MirageOS unikernels with Guix, which means using the OPAM importer *a lot*, which unearths some very Fun TM bugs. Here is the first one:
guix import opam mirage-clock
The correct check phase is this:
```
(replace 'check
(lambda* (#:key tests? #:allow-other-keys)
(invoke "dune" "runtest" "--release")))
```
