f27-ocaml2 target has been created:

$ koji add-tag f27-ocaml2 --parent=f27-build --arches="aarch64 armv7hl i686 ppc64 ppc64le s390x x86_64"
$ koji add-target f27-ocaml2 f27-ocaml2

You can do builds with:

$ fedpkg build --target=f27-ocaml2

let us know when you are done and we will move all the builds into f27.

Currently blocked on https://bugzilla.redhat.com/show_bug.cgi?id=1470692

After discussion on IRC we decided to let the F27 Mass Rebuild go ahead before doing the OCaml 4.05 rebuild.

For this reason I untagged the ocaml-4.05.0-1.fc27 package from f27-ocaml2 and reverted the change in dist-git.

We'll continue with this after the Mass Rebuild has done.

This is running again now. The following link shows the builds against the f27-ocaml2 tag:
https://koji.fedoraproject.org/koji/builds?inherited=0&tagID=1838&order=-build_id&latest=1

We're ready to merge this in.

The following packages failed to rebuild:
* coq + packages that depend on it: Some issue with binutils 2.29 and aarch64, being discussed upstream: https://github.com/ocaml/ocaml/pull/1268
* ocaml-gsl and ocaml-lacaml: Some problem with linking to atlas which may also be caused by binutils, see my post on devel list.
* ocaml-camlimages: Fails to build debugsource for reasons which I don't understand and cannot reproduce with local builds.

Merged.

$ ./mass-tag.py --source f27-ocaml2 --target f27-pending
Checking 87 builds...
Tagging alt-ergo-1.30-9.fc27 into f27-pending
Tagging apron-0.9.11-11.1097.svn20160801.fc27 into f27-pending
Tagging brltty-5.5-8.fc27 into f27-pending
Tagging cduce-0.6.0-30.fc27 into f27-pending
Tagging coccinelle-1.0.6-14.fc27 into f27-pending
Tagging graphviz-2.40.1-10.fc27 into f27-pending
Tagging guestfs-browser-0.2.3-10.fc27 into f27-pending
Tagging hevea-2.30-3.fc27 into f27-pending
Tagging hivex-1.3.14-8.fc27 into f27-pending
Tagging libguestfs-1.37.20-2.fc27 into f27-pending
Tagging ocaml-4.05.0-2.fc27 into f27-pending
Tagging ocaml-SDL-0.9.1-24.fc27 into f27-pending
Tagging ocaml-ancient-0.9.0-34.fc27 into f27-pending
Tagging ocaml-augeas-0.5-26.fc27 into f27-pending
Tagging ocaml-base64-2.1.2-8.fc27 into f27-pending
Tagging ocaml-bin-prot-2.0.9-28.fc27 into f27-pending
Tagging ocaml-biniou-1.0.9-26.fc27 into f27-pending
Tagging ocaml-bisect-1.3-21.fc27 into f27-pending
Tagging ocaml-bitstring-2.0.4-23.fc27 into f27-pending
Tagging ocaml-cairo-0.4.7-0.16.gitbe5a298.fc27 into f27-pending
Tagging ocaml-calendar-2.04-12.fc27 into f27-pending
Tagging ocaml-camlidl-1.05-42.fc27 into f27-pending
Tagging ocaml-camlimages-4.2.4-1.fc27 into f27-pending
Tagging ocaml-camlp4-4.05.0-0.4.gitfc12d8c7.fc27 into f27-pending
Tagging ocaml-camlp5-7.00-4.fc27 into f27-pending
Tagging ocaml-camomile-0.8.6-0.1.git3f4d657d.fc27 into f27-pending
Tagging ocaml-cil-1.7.3-38.fc27 into f27-pending
Tagging ocaml-cppo-1.5.0-5.fc27 into f27-pending
Tagging ocaml-cryptokit-1.11-8.fc27 into f27-pending
Tagging ocaml-csv-1.3.1-23.fc27 into f27-pending
Tagging ocaml-curl-0.7.9-8.fc27 into f27-pending
Tagging ocaml-curses-1.0.3-40.fc27 into f27-pending
Tagging ocaml-dbus-0.30-11.fc27 into f27-pending
Tagging ocaml-deriving-0.1.2-10.fc27 into f27-pending
Tagging ocaml-easy-format-1.0.2-22.fc27 into f27-pending
Tagging ocaml-expat-0.9.1-46.fc27 into f27-pending
Tagging ocaml-extlib-1.7.2-5.fc27 into f27-pending
Tagging ocaml-facile-1.1-44.fc27 into f27-pending
Tagging ocaml-fileutils-0.5.1-8.fc27 into f27-pending
Tagging ocaml-findlib-1.7.3-5.fc27 into f27-pending
Tagging ocaml-gettext-0.3.5-17.fc27 into f27-pending
Tagging ocaml-json-static-0.9.8-31.fc27 into f27-pending
Tagging ocaml-json-wheel-1.0.6-34.fc27 into f27-pending
Tagging ocaml-lablgl-1.05-25.fc27 into f27-pending
Tagging ocaml-lablgtk-2.18.5-9.fc27 into f27-pending
Tagging ocaml-labltk-8.06.3-1.fc27 into f27-pending
Tagging ocaml-libvirt-0.6.1.4-21.fc27 into f27-pending
Tagging ocaml-lwt-2.5.0-15.fc27 into f27-pending
Tagging ocaml-menhir-20170712-4.fc27 into f27-pending
Tagging ocaml-mikmatch-1.0.9-0.8.git8a892254.fc27 into f27-pending
Tagging ocaml-mlgmpidl-1.2.1-0.27.20150921.fc27 into f27-pending
Tagging ocaml-mysql-1.2.1-9.fc27 into f27-pending
Tagging ocaml-newt-0.9-37.fc27 into f27-pending
Tagging ocaml-ocamlbuild-0.11.0-9.fc27 into f27-pending
Tagging ocaml-ocamlgraph-1.8.7-10.fc27 into f27-pending
Tagging ocaml-ocamlnet-4.1.3-1.fc27 into f27-pending
Tagging ocaml-ocplib-simplex-0.3-8.fc27 into f27-pending
Tagging ocaml-omake-0.9.8.6-0.rc1.fc27.29 into f27-pending
Tagging ocaml-openin-20070524-40.fc27 into f27-pending
Tagging ocaml-ounit-2.0.0-27.fc27 into f27-pending
Tagging ocaml-p3l-2.03-37.fc27 into f27-pending
Tagging ocaml-pa-monad-6.0-34.fc27 into f27-pending
Tagging ocaml-pcre-7.2.3-8.fc27 into f27-pending
Tagging ocaml-perl4caml-0.9.5-55.fc27 into f27-pending
Tagging ocaml-pgocaml-1.6-27.fc27 into f27-pending
Tagging ocaml-postgresql-4.0.1-8.fc27 into f27-pending
Tagging ocaml-preludeml-0.1-0.45.20100314.fc27 into f27-pending
Tagging ocaml-pxp-1.2.8-7.fc27 into f27-pending
Tagging ocaml-react-1.2.0-10.fc27 into f27-pending
Tagging ocaml-res-4.0.7-8.fc27 into f27-pending
Tagging ocaml-sexplib-7.0.5-27.fc27 into f27-pending
Tagging ocaml-sqlite-4.0.6-8.fc27 into f27-pending
Tagging ocaml-srpm-macros-5-2.fc27 into f27-pending
Tagging ocaml-ssl-0.5.2-10.fc27 into f27-pending
Tagging ocaml-tplib-1.3-29.fc27 into f27-pending
Tagging ocaml-type-conv-3.0.5-28.fc27 into f27-pending
Tagging ocaml-ulex-1.1-37.fc27 into f27-pending
Tagging ocaml-xml-light-2.3-0.26.svn234.fc27 into f27-pending
Tagging ocaml-xmlm-1.2.0-24.fc27 into f27-pending
Tagging ocaml-xmlrpc-light-0.6.1-40.fc27 into f27-pending
Tagging ocaml-yojson-1.1.8-24.fc27 into f27-pending
Tagging ocaml-zarith-1.4.1-11.fc27 into f27-pending
Tagging ocaml-zip-1.06-8.fc27 into f27-pending
Tagging ocamldsort-0.16.0-7.fc27 into f27-pending
Tagging plplot-5.12.0-5.fc27 into f27-pending
Tagging virt-top-1.0.8-27.fc27 into f27-pending
Tagging z3-4.5.0-6.fc27 into f27-pending
Tagging 87 builds.
Tagged 87 builds.

Excellent thanks.