Unable to compile on ocaml multicore

[pklehre]

I get the following error message when trying to install stdcompat via opam:

[pkl@zeta ~]$ opam install stdcompat
The following actions will be performed:
  ∗ install stdcompat 16

<><> Gathering sources ><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
[stdcompat.16] found in cache

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
[ERROR] The compilation of stdcompat failed at "/home/pkl/.opam/opam-init/hooks/sandbox.sh build make all".

#=== ERROR while compiling stdcompat.16 =======================================#
# context     2.0.7 | linux/x86_64 | ocaml-variants.4.12.0+domains | https://opam.ocaml.org/#5c5a526e
# path        ~/.opam/4.12.0+domains/.opam-switch/build/stdcompat.16
# command     ~/.opam/opam-init/hooks/sandbox.sh build make all
# exit-code   2
# env-file    ~/.opam/log/stdcompat-112897-6d07ae.env
# output-file ~/.opam/log/stdcompat-112897-6d07ae.out
### output ###
# [...]
# ocamlfind ocamlopt -c -package seq -package uchar -bin-annot -no-alias-deps -nolabels -I . -alert -deprecated stdcompat__printexc_s.mli -o stdcompat__printexc_s.cmi
# ocamlfind ocamlopt -c -package seq -package uchar -bin-annot -no-alias-deps -nolabels -I . -alert -deprecated stdcompat__format_s.mli -o stdcompat__format_s.cmi
# ocamlfind ocamlopt -c -package seq -package uchar -bin-annot -no-alias-deps -nolabels -I . -alert -deprecated stdcompat__atomic_s.mli -o stdcompat__atomic_s.cmi
# File "stdcompat__atomic_s.mli", line 4, characters 0-24:
# 4 | type !'a t = 'a Atomic.t
#     ^^^^^^^^^^^^^^^^^^^^^^^^
# Error: In this definition, expected parameter variances are not satisfied.
#        The 1st type parameter was expected to be injective invariant,
#        but it is invariant.
# make[1]: *** [Makefile:1651: stdcompat__atomic_s.cmi] Error 2
# make[1]: Leaving directory '/home/pkl/.opam/4.12.0+domains/.opam-switch/build/stdcompat.16'
# make: *** [Makefile:836: all] Error 2



<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
┌─ The following actions failed
│ λ build stdcompat 16
└─ 
╶─ No changes have been performed