cca doesn't compile on a fresh switch

[reynir]

I personally don't use cca, and I discovered the issue during the release of awa 0.5.2. See below:

---

It seems it's an issue with cca:

$ opam switch create cca
[...]
[ERROR] The compilation of cca.0.7 failed at "make -C src/ast/analyzing production".

#=== ERROR while compiling cca.0.7 ============================================#
# context     2.3.0 | linux/x86_64 |  | https://opam.ocaml.org#dbc9ec7b83bac3673185542221a571372b6abb35
# path        ~/.opam/cca/.opam-switch/build/cca.0.7
# command     ~/.opam/opam-init/hooks/sandbox.sh build make -C src/ast/analyzing production
# exit-code   2
# env-file    ~/.opam/log/cca-15091-b70157.env
# output-file ~/.opam/log/cca-15091-b70157.out
### output ###
# [...]
# findlib: [WARNING] Interface ratio.cmi occurs in several directories: /home/reynir/.opam/cca/lib/num, /home/reynir/.opam/cca/lib/ocaml
# findlib: [WARNING] Interface num.cmi occurs in several directories: /home/reynir/.opam/cca/lib/num, /home/reynir/.opam/cca/lib/ocaml
# ocamlfind: [WARNING] Package `mtime.clock.os': Deprecated, use the mtime.clock library.
# File "_none_", line 1:
# Error: No implementations provided for the following modules:
#          Mirage_ptime referenced from /home/reynir/.opam/cca/lib/ca-certs-nss/ca_certs_nss.cmxa(Ca_certs_nss),
#            /home/reynir/.opam/cca/lib/tls-mirage/tls_mirage.cmxa(Tls_mirage),
#            /home/reynir/.opam/cca/lib/git-mirage/http/git_mirage_http.cmxa(Git_mirage_http)
#          Mirage_sleep referenced from /home/reynir/.opam/cca/lib/awa-mirage/awa_mirage.cmxa(Awa_mirage)
#          Mirage_mtime referenced from /home/reynir/.opam/cca/lib/awa-mirage/awa_mirage.cmxa(Awa_mirage)
# make: *** [Makefile:220: bin/ogit.opt] Error 2
# make: Leaving directory '/home/reynir/.opam/cca/.opam-switch/build/cca.0.7/src/ast/analyzing'
[...]
$ opam pin list
$ 

Originally posted by @reynir in #27942 (comment)

[reynir]

Ping @codinuum who seems to be the maintainer :-)

[mseri]

For the released packages, this should be enough to fix it: #27954
But for future releases something should be done in the build scripts