Follow the deprecation message of "Mirage_crypto_rng_lwt.initialize"

[boechat107]

I came across the following deprecation error when trying to build dream today:

▶ make build                                                                                                                                           
File "src/dream.ml", line 59, characters 4-36:                                                                                         
59 |     Mirage_crypto_rng_lwt.initialize (module Mirage_crypto_rng.Fortuna))
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^       
Error (alert deprecated): Mirage_crypto_rng_lwt.initialize                                                                             
Use 'Mirage_crypto_rng_unix.use_default ()' instead.                                                                                   
make: *** [Makefile:5: build] Error 1

And these are my installed packages:

▶ opam list | grep crypto                                          
mirage-crypto            1.2.0        Simple symmetric cryptography for the modern age
mirage-crypto-ec         1.2.0        Elliptic Curve Cryptography with primitives taken from Fiat
mirage-crypto-pk         1.2.0        Simple public-key cryptography for the modern age
mirage-crypto-rng        1.2.0        A cryptographically secure PRNG
mirage-crypto-rng-lwt    1.2.0        A cryptographically secure PRNG
mirage-crypto-rng-mirage 1.2.0        Entropy collection for a cryptographically secure PRNG

I confirmed the deprecation from mirage-crypto release notes for 1.2.0.

[hannesm]

Suggested change

"mirage-crypto-rng-lwt"

[hannesm]

looks fine, but in src/dune, you should replace the mirage-crypto-rng-lwt with mirage-crypto-rng.unix.

[hannesm]

and the example/z-playground/opam-switch needs to be updated/regenerated.

[boechat107]

and the example/z-playground/opam-switch needs to be updated/regenerated.

Is it enough to simply remove mirage-crypto-rng-lwt from opam-switch? Or is there another process to follow?

[aantron]

Thank you!

I took the playground down for now as I had no time to maintain it, so we will deal with its opam-switch file later.

[aantron]

This was also done as part of #393 by @Willenbrink and #395 by @hannesm, but those PRs have other contributions so I'll merge them as contributing those.