opam and eliom -> [eliom: make]Killed

[MdeLv]

debian 11
opam 2.1.4

On one server, each ocsigen-start update I get "[eliom: make]Killed" and the configuration is broken. So I need to do opam install ocsigen-start . This does not happen on another server (same debian and opam versions).
There is enough storage.

Here is the eliom-*.out log:

~$ tail .opam/log/eliom-3850931-568e09.out 
ocamlfind ocamlc -c -g -keep-locs -thread -package js_of_ocaml-ppx_deriving_json -package js_of_ocaml-ppx -package xml-light -package react,lwt_react,js_of_ocaml -package lwt,ocsigenserver,ocsipersist,tyxml.functor -package js_of_ocaml-ppx_deriving_json,lwt_ppx -w +A-4-6-7@8-9@11@12-16@20@23@24@26@[email protected]@38-39-40@41-42@43-44@45-48-63-67@68-69-70 -I /home/ml/.opam/4.14.0/lib/js_of_ocaml -I src/lib -I src/lib/server -o src/lib/server/eliom_wrap.cmo src/lib/server/eliom_wrap.ml
ocamlfind ocamlc -c -g -keep-locs -thread -package js_of_ocaml-ppx_deriving_json -package js_of_ocaml-ppx -package xml-light -package react,lwt_react,js_of_ocaml -package lwt,ocsigenserver,ocsipersist,tyxml.functor -package js_of_ocaml-ppx_deriving_json,lwt_ppx -w +A-4-6-7@8-9@11@12-16@20@23@24@26@[email protected]@38-39-40@41-42@43-44@45-48-63-67@68-69-70 -I /home/ml/.opam/4.14.0/lib/js_of_ocaml -I src/lib -I src/lib/server -o src/lib/server/eliom_comet_base.cmo src/lib/server/eliom_comet_base.ml
ocamlfind ocamlc -c -g -keep-locs -thread -package js_of_ocaml-ppx_deriving_json -package js_of_ocaml-ppx -package xml-light -package react,lwt_react,js_of_ocaml -package lwt,ocsigenserver,ocsipersist,tyxml.functor -package js_of_ocaml-ppx_deriving_json,lwt_ppx -w +A-4-6-7@8-9@11@12-16@20@23@24@26@[email protected]@38-39-40@41-42@43-44@45-48-63-67@68-69-70 -I /home/ml/.opam/4.14.0/lib/js_of_ocaml -I src/lib -I src/lib/server -o src/lib/server/eliom_runtime.cmo src/lib/server/eliom_runtime.ml
ocamlfind ocamlc -c -g -keep-locs -thread -package js_of_ocaml-ppx_deriving_json -package js_of_ocaml-ppx -package xml-light -package react,lwt_react,js_of_ocaml -package lwt,ocsigenserver,ocsipersist,tyxml.functor -package js_of_ocaml-ppx_deriving_json,lwt_ppx -w +A-4-6-7@8-9@11@12-16@20@23@24@26@[email protected]@38-39-40@41-42@43-44@45-48-63-67@68-69-70 -I /home/ml/.opam/4.14.0/lib/js_of_ocaml -I src/lib -I src/lib/server -o src/lib/server/eliom_content_core.cmo src/lib/server/eliom_content_core.ml
ocamlfind ocamlc -c -g -keep-locs -thread -package js_of_ocaml-ppx_deriving_json -package js_of_ocaml-ppx -package xml-light -package react,lwt_react,js_of_ocaml -package lwt,ocsigenserver,ocsipersist,tyxml.functor -package js_of_ocaml-ppx_deriving_json,lwt_ppx -w +A-4-6-7@8-9@11@12-16@20@23@24@26@[email protected]@38-39-40@41-42@43-44@45-48-63-67@68-69-70 -ppx 'src/ppx/ppx_eliom_server_ex.native -type src/lib/type_dir/eliom_form.inferred_gen.mli' -I /home/ml/.opam/4.14.0/lib/js_of_ocaml -I src/lib -I src/lib/server -o src/lib/server/eliom_form.cmo src/lib/server/eliom_form.ml
+ ocamlfind ocamlc -c -g -keep-locs -thread -package js_of_ocaml-ppx_deriving_json -package js_of_ocaml-ppx -package xml-light -package react,lwt_react,js_of_ocaml -package lwt,ocsigenserver,ocsipersist,tyxml.functor -package js_of_ocaml-ppx_deriving_json,lwt_ppx -w +A-4-6-7@8-9@11@12-16@20@23@24@26@[email protected]@38-39-40@41-42@43-44@45-48-63-67@68-69-70 -ppx 'src/ppx/ppx_eliom_server_ex.native -type src/lib/type_dir/eliom_form.inferred_gen.mli' -I /home/ml/.opam/4.14.0/lib/js_of_ocaml -I src/lib -I src/lib/server -o src/lib/server/eliom_form.cmo src/lib/server/eliom_form.ml
File "src/lib/server/eliom_form.ml", line 1:
Error: I/O error: src/lib/server/eliom_form.cmi9c56b6.tmp: No such file or directory
Command exited with code 2.
Fatal error: exception Sys_error("/home/ml/.opam/4.14.0/.opam-switch/build/eliom.10.0.0/_build/_digests: No such file or directory")

How to fix that?

PS: What are the real depends of eliom and ocsigen-start packages?

[MdeLv]

Again, in the same context, same message [eliom: make]Killed on the same host while not on the other.
This time I can't see "No such file or directory" in the file eliom--.out

I can see some lines with the word "error":

$ cat eliom-1251497-3bdb92.out | grep --color "error"
ocamlfind ocamldep -package js_of_ocaml-ppx_deriving_json -package js_of_ocaml-ppx -package xml-light -package react,lwt_react,js_of_ocaml -package lwt,ocsigenserver,ocsipersist,tyxml.functor -package js_of_ocaml-ppx_deriving_json,lwt_ppx -modules src/lib/server/eliom_error_pages.ml > src/lib/server/eliom_error_pages.ml.depends
ocamlfind ocamlc -c -g -keep-locs -thread -package js_of_ocaml-ppx_deriving_json -package js_of_ocaml-ppx -package xml-light -package react,lwt_react,js_of_ocaml -package lwt,ocsigenserver,ocsipersist,tyxml.functor -package js_of_ocaml-ppx_deriving_json,lwt_ppx -w +A-4-6-7@8-9@11@12-16@20@23@24@26@[email protected]@38-39-40@41-42@43-44@45-48-63-67@68-69-70 -I /home/lm/.opam/4.14.0/lib/js_of_ocaml -I src/lib -I src/lib/server -o src/lib/server/eliom_error_pages.cmo src/lib/server/eliom_error_pages.ml

How to get information about the cause of that trouble?