OCaml 4.03 has been out for a while.
I'm intending to add it to Fedora Rawhide once a side tag has been created: https://fedorahosted.org/rel-eng/ticket/6486
This will require rebuilding every OCaml package, which I normally do using a script, but probably there will be manual rebuilds necessary too.
A few issues that may affect people:
(1) There is a new ppc backend upstream, and I intend to switch to this.
For years we have maintained our own out-of-tree ppc64 & ppc64le backends. I want to switch to the upstream ppc backend (which supports, in theory, ppc 32 bit, ppc64 and ppc64le). However when I actually tried this I found it to be rather buggy, it couldn't even compile many basic OCaml packages. This time I intend to switch, and we'll deal with the bugs.
(2) There is a new s/390x backend upstream. This should enable us to compile all s/390x packages as native code.
It also means that all supported architectures (yes, even riscv64) will support native compilation for OCaml.
(3) The real reason I'm doing this now is because partners have asked us to update the OCaml compiler in RHEL 7.4. This will be a binary ABI break -- it's unfortunately unavoidable -- and will require all OCaml-using programs to be recompiled, and of course that will affect CentOS and any other RHEL derivatives.
Rich.