I tried on both 4.09 and 4.11 and couldn't get it to work. Also I couldn't find a `--dev-deps` flag, did you mean `--deps-only'? That didn't work either. I'll wait for the fix David Allsopp mentioned and try again. martin On Sun, Dec 6, 2020 at 1:41 AM Fabrice Le Fessant < fabrice.le_fessant@origin-labs.com> wrote: > Hi Martin, > > I have a 4.09.1 switch with both core_kernel.v0.14.1 and drom.0.2.0 > installed with no conflict. Did you try to install with dev-deps ? > > Best regards > -- > Fabrice > > On Sun, Dec 6, 2020 at 4:06 AM Martin DeMello > wrote: > > > > I tried to install drom via opam and got told that it conflicted with > core_kernel: > > > > ⊘ remove core_kernel v0.14.1 [conflicts with > opam-file-format] > > ↗ upgrade opam-file-format 2.1.0 to 2.1.1 [required by drom_lib] > > > > but `opam show core_kernel` lists no dependency on opam-file-format`, > and `opam show opam-file-format.2.1.1` just says > > > > depends: "ocaml" "dune" {>= "2.0"} "alcotest" {with-test} > > conflicts: "core_kernel" > > > > with no indication as to why the conflict. > > > > martin >