Hello,

here's the error:

```
guix/import/crate.scm:283:18: In procedure dependency-name+version:
In procedure struct-vtable: Wrong type argument in position 1 (expecting 
struct): #f
```

I guess the issue is that cranelift-codegen is memoized with (mproc 
"cranelift-codegen" #:version "0.68.0" #:repo #f …) , where repo is 
false. but it seems to have a repo on the page? 
https://crates.io/crates/cranelift-codegen?

I'll try and work towards a fix sometime next month, but I'd be glad
for some pointers.

Thank you,
Abhishek.