mirage-crypto & fiat-p256 does not work with newer eqaf (requires the .cstruct package)

[hannesm]

for #26094

=== ERROR while compiling mirage-crypto.0.11.0 ===============================#
 context              2.2.0~beta3~dev | linux/x86_64 | ocaml-base-compiler.4.14.2 | file:///home/opam/opam-repository
 path                 ~/.opam/4.14/.opam-switch/build/mirage-crypto.0.11.0
 command              ~/.opam/opam-init/hooks/sandbox.sh build dune build -p mirage-crypto -j 255
 exit-code            1
 env-file             ~/.opam/log/mirage-crypto-7-db30d0.env
 output-file          ~/.opam/log/mirage-crypto-7-db30d0.out
 ## output ###
 File "src/dune", line 4, characters 20-32:
 4 |  (libraries cstruct eqaf.cstruct)
                         ^^^^^^^^^^^^
 Error: Library "eqaf.cstruct" not found.
 -> required by library "mirage-crypto" in _build/default/src
 -> required by _build/default/META.mirage-crypto
 -> required by _build/install/default/lib/mirage-crypto/META
 -> required by _build/default/mirage-crypto.install
 -> required by alias install

[raphael-proust]

Causes build failures on windows but seems to be that -pedantic causes C compiler incompatibilities to become fatal:

 #=== ERROR while compiling mirage-crypto.0.9.2 ================================#
# context              2.2.0~beta3 | win32/x86_64 | ocaml.5.2.0 | file://D:/a/opam-repository/opam-repository
# path                 D:\opamroot\default\.opam-switch\build\mirage-crypto.0.9.2
# command              D:\opamroot\default\bin\dune.exe build -p mirage-crypto -j 3
# exit-code            1
# env-file             D:\opamroot\log\mirage-crypto-8120-f95a93.env
# output-file          D:\opamroot\log\mirage-crypto-8120-f95a93.out
### output ###
# [...]
# D:/opamroot/default/lib/ocaml/caml/misc.h:207:8: warning: ISO C99 does not support the '_Atomic' qualifier [-Wpedantic]
#   207 | extern _Atomic caml_timing_hook caml_finalise_begin_hook;
#       |        ^~~~~~~
# D:/opamroot/default/lib/ocaml/caml/misc.h:208:8: warning: ISO C99 does not support the '_Atomic' qualifier [-Wpedantic]
#   208 | extern _Atomic caml_timing_hook caml_finalise_end_hook;
#       |        ^~~~~~~
# D:/opamroot/default/lib/ocaml/caml/misc.h:209:8: warning: ISO C99 does not support the '_Atomic' qualifier [-Wpedantic]
#   209 | extern _Atomic caml_timing_hook caml_domain_terminated_hook;
#       |        ^~~~~~~
# D:/opamroot/default/lib/ocaml/caml/misc.h:301:8: warning: ISO C99 does not support the '_Atomic' qualifier [-Wpedantic]
#   301 | extern _Atomic fatal_error_hook caml_fatal_error_hook;
#       |        ^~~~~~~

It's not blocking for this PR but it's possibly something to look at later.

[raphael-proust]

The CI has some issue with alcotest dependency. Probably missing a version constraint:

#=== ERROR while compiling fiat-p256.0.2.1 ====================================#
# context              2.2.0~beta3~dev | linux/x86_64 | ocaml-base-compiler.4.04.2 | pinned(https://github.com/mirage/fiat/releases/download/v0.2.1/fiat-p256-v0.2.1.tbz)
# path                 ~/.opam/4.04/.opam-switch/build/fiat-p256.0.2.1
# command              ~/.opam/opam-init/hooks/sandbox.sh build dune runtest -p fiat-p256 -j 255
# exit-code            1
# env-file             ~/.opam/log/fiat-p256-7-6ee0be.env
# output-file          ~/.opam/log/fiat-p256-7-6ee0be.out
### output ###
# (cd _build/default && /home/opam/.opam/4.04/bin/ocamlopt.opt -w -40 -g -I test/unit/.test_p256.eobjs/byte -I test/unit/.test_p256.eobjs/native -I /home/opam/.opam/4.04/lib/alcotest -I /home/opam/.opam/4.04/lib/bigarray-compat -I /home/opam/.opam/4.04/lib/bytes -I /home/opam/.opam/4.04/lib/cmdliner -I /home/opam/.opam/4.04/lib/cstruct -I /home/opam/.opam/4.04/lib/eqaf -I /home/opam/.opam/4.04/lib/eqaf/bigstring -I /home/opam/.opam/4.04/lib/eqaf/cstruct -I /home/opam/.opam/4.04/lib/hex -I /home/opam/.opam/4.04/lib/stringext -I p256/.fiat_p256.objs/byte -I p256/.fiat_p256.objs/native -intf-suffix .ml -no-alias-deps -o test/unit/.test_p256.eobjs/native/test_p256.cmx -c -impl test/unit/test_p256.ml)
# File "test/unit/test_p256.ml", line 2, characters 19-36:
# Error: Unbound value Alcotest.testable
# (cd _build/default && /home/opam/.opam/4.04/bin/ocamlopt.opt -w -40 -g -I test/functional/.test_fiat_p256.eobjs/byte -I test/functional/.test_fiat_p256.eobjs/native -I /home/opam/.opam/4.04/lib/alcotest -I /home/opam/.opam/4.04/lib/bigarray-compat -I /home/opam/.opam/4.04/lib/bytes -I /home/opam/.opam/4.04/lib/cmdliner -I /home/opam/.opam/4.04/lib/cstruct -I /home/opam/.opam/4.04/lib/eqaf -I /home/opam/.opam/4.04/lib/eqaf/bigstring -I /home/opam/.opam/4.04/lib/eqaf/cstruct -I /home/opam/.opam/4.04/lib/hex -I /home/opam/.opam/4.04/lib/result -I /home/opam/.opam/4.04/lib/rresult -I /home/opam/.opam/4.04/lib/stringext -I p256/.fiat_p256.objs/byte -I p256/.fiat_p256.objs/native -intf-suffix .ml -no-alias-deps -o test/functional/.test_fiat_p256.eobjs/native/test_fiat_p256.cmx -c -impl test/functional/test_fiat_p256.ml)
# File "test/functional/test_fiat_p256.ml", line 4, characters 4-21:
# Error: Unbound value Alcotest.testable
# (cd _build/default && /home/opam/.opam/4.04/bin/ocamlopt.opt -w -40 -g -I test/wycheproof/.test.eobjs/byte -I test/wycheproof/.test.eobjs/native -I /home/opam/.opam/4.04/lib/alcotest -I /home/opam/.opam/4.04/lib/asn1-combinators -I /home/opam/.opam/4.04/lib/bigarray-compat -I /home/opam/.opam/4.04/lib/bytes -I /home/opam/.opam/4.04/lib/cmdliner -I /home/opam/.opam/4.04/lib/cstruct -I /home/opam/.opam/4.04/lib/eqaf -I /home/opam/.opam/4.04/lib/eqaf/bigstring -I /home/opam/.opam/4.04/lib/eqaf/cstruct -I /home/opam/.opam/4.04/lib/hex -I /home/opam/.opam/4.04/lib/ppx_deriving/runtime -I /home/opam/.opam/4.04/lib/ppx_deriving_yojson/runtime -I /home/opam/.opam/4.04/lib/result -I /home/opam/.opam/4.04/lib/seq -I /home/opam/.opam/4.04/lib/stringext -I /home/opam/.opam/4.04/lib/yojson -I /home/opam/.opam/4.04/lib/zarith -I p256/.fiat_p256.objs/byte -I p256/.fiat_p256.objs/native -I test/helpers/wycheproof/.wycheproof.objs/byte -I test/helpers/wycheproof/.wycheproof.objs/native -intf-suffix .ml -no-alias-deps -o test/wycheproof/.test.eobjs/native/test.cmx -c -impl test/wycheproof/test.ml)
# File "test/wycheproof/test.ml", line 3, characters 10-27:
# Error: Unbound value Alcotest.testable

Not blocking this PR because it's unrelated maintenance. But still maybe something to fix later. (Or something to base archiving decisions on.)

[hannesm]

Thanks for your review, @raphael-proust. There's no plan to fix all the issues the CI encountered for this PR. We can have separate issues open for the problems you encountered. But it is likely only interesting for historical reasons, since soon we'll get another release of mirage-crypto to continue the work on.

TL;DR: this PR is fine to merge. It only adjusts some bounds.

[dinosaure]

For me, it's also ok to merge 👍.

[raphael-proust]

Thanks for the contribution! This is a strict improvement so all the remaining problems are left as is for now…