eio_main 0.5

Error log

The package failed to build. The error log from opam follows.

Opam plugin "depext" may require upgrading/reinstalling. Reinstall the plugin on the current switch? [Y/n] y
The following actions will be performed:
  - recompile opam-depext 1.2.1-1

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
-> retrieved opam-depext.1.2.1-1  (cached)
-> removed   opam-depext.1.2.1-1
-> installed opam-depext.1.2.1-1
Done.

<><> opam-depext.1.2.1-1 installed successfully <><><><><><><><><><><><><><><><>
=> opam-depext is unnecessary when used with opam >= 2.1. Please use opam install directly instead
# Run eval $(opam env) to update the current shell environment

<><> Carrying on to "opam depext -viy eio_main.0.5 uring.0.8 topkg.1.0.7 stdlib-shims.0.3.0 seq.base psq.0.2.1 optint.0.3.0 ocamlfind.1.9.6 ocamlbuild.0.14.3 mtime.2.0.0 lwt-dllist.1.0.1 luv_unix.0.5.1 luv.0.5.12 logs.0.7.0 integers.0.7.0 hmap.0.8.1 fmt.0.9.0 eio_luv.0.5 eio_linux.0.5 eio.0.5 dune-configurator.3.13.0 dune.3.13.0 ctypes.0.21.1 cstruct.6.2.0 csexp.1.5.2 bigstringaf.0.9.1 bigarray-compat.1.1.0" 

You are using opam 2.1+, where external dependency handling has been integrated: consider calling opam directly, the 'depext' plugin interface is provided for backwards compatibility only
# Detecting depexts using vars: arch=x86_64, os=linux, os-distribution=debian, os-family=debian
[ERROR] No solution for eio_main.0.5 & uring.0.8 & topkg.1.0.7 & stdlib-shims.0.3.0 & seq.base & psq.0.2.1 & optint.0.3.0 & ocamlfind.1.9.6 & ocamlbuild.0.14.3 & mtime.2.0.0 & lwt-dllist.1.0.1 & luv_unix.0.5.1 & luv.0.5.12 & logs.0.7.0 & integers.0.7.0 & hmap.0.8.1 & fmt.0.9.0 & eio_luv.0.5 & eio_linux.0.5 & eio.0.5 & dune-configurator.3.13.0 & dune.3.13.0 & ctypes.0.21.1 & cstruct.6.2.0 & csexp.1.5.2 & bigstringaf.0.9.1 & bigarray-compat.1.1.0:   * Incompatible packages:
            - (invariant) -> ocaml-base-compiler = 5.0.0
            - eio = 0.5
            You can temporarily relax the switch invariant with `--update-invariant'


Command failed: opam --cli=2.1 list --readonly --external '--resolve=eio_main.0.5,uring.0.8,topkg.1.0.7,stdlib-shims.0.3.0,seq.base,psq.0.2.1,optint.0.3.0,ocamlfind.1.9.6,ocamlbuild.0.14.3,mtime.2.0.0,lwt-dllist.1.0.1,luv_unix.0.5.1,luv.0.5.12,logs.0.7.0,integers.0.7.0,hmap.0.8.1,fmt.0.9.0,eio_luv.0.5,eio_linux.0.5,eio.0.5,dune-configurator.3.13.0,dune.3.13.0,ctypes.0.21.1,cstruct.6.2.0,csexp.1.5.2,bigstringaf.0.9.1,bigarray-compat.1.1.0' returned 20