Cache dependencies in mhs

[MaximilianAlgehed]

This bring the mhs job down from a bit over 5 mins to a bit under 4, the majority of what's left is building mhs itself.

[MaximilianAlgehed]

@augustss Anything dangerous and/or stupid about what I'm doing here?

[MaximilianAlgehed]

Also, any chance of speeding up make minstall up by caching things?

[augustss]

I'll take a look.

[sol]

This bring the mhs job down from a bit over 5 mins to a bit under 4

Is it safe to share build products across mhs versions?

the majority of what's left is building mhs itself

#454 addresses this. (still pending upstream changes)

[MaximilianAlgehed]

Is it safe to share build products across mhs versions?

Good point - probably not in general.

#454 addresses this. (still pending upstream changes)

I'm glad your PR let's me elegantly get around the issue above! Thanks!

[sol]

I think technically you could do nightly builds of mhs + all the libraries that are known to work and provide these via a GitHub action (Stackage-like).

This should make it as fast as it can get.

I'm gonna give this a try in a separate repository.

[sol]

This brings the CI run down to 1m 26s.

[MaximilianAlgehed]

I expect this will make little to no difference after @sol's brilliant contribution.