Uncaught exception:
  
  (Invalid_argument
   "Float.iround_nearest_exn: argument (nan) is too small or NaN")

Raised at Stdlib.invalid_arg in file "stdlib.ml", line 30, characters 20-45
Called from Base__Float.iround_nearest_exn_64 in file "src/float.ml" (inlined), line 360, characters 4-89
Called from Base__Float.int63_round_nearest_arch64_noalloc_exn in file "src/float.ml", line 514, characters 60-82
Called from Time_stamp_counter.Calibrator.calibrate_using in file "time_stamp_counter/src/time_stamp_counter.ml" (inlined), line 277, characters 7-69
Called from Time_stamp_counter.Calibrator.initialize.(fun) in file "time_stamp_counter/src/time_stamp_counter.ml", line 285, characters 6-56
Called from Base__List0.iter in file "src/list0.ml", line 60, characters 4-7
Called from Time_stamp_counter.Calibrator.create_using in file "time_stamp_counter/src/time_stamp_counter.ml", line 322, characters 4-24

#=== ERROR while compiling core_unix.v0.15~preview.126.02+18 ==================#
# context     2.1.0 | macos/x86_64 | ocaml-base-compiler.4.11.1 | https://ocaml.janestreet.com/opam-repository
# path        ~/Documents/abc/_opam/.opam-switch/build/core_unix.v0.15~preview.126.02+18
# command     ~/.opam/opam-init/hooks/sandbox.sh build dune build -p core_unix -j 11
# exit-code   1
# env-file    ~/.opam/log/core_unix-12447-6904f5.env
# output-file ~/.opam/log/core_unix-12447-6904f5.out
### output ###
# Error: Unbound module Spawn.Pgid
# [...]
# (cd _build/default && /Users/denis.grebennicov/Documents/abc/_opam/bin/ocamlc.opt -w -40 -g -bin-annot -I linux_ext/src/.linux_ext.objs/byte -I /Users/denis.grebennicov/Documents/mongo_utils/_opam/lib/base -I /Users/denis.grebennicov/Documents/mongo_utils/_opam/lib/base/base_internalhash_types -I /Users/denis.grebennicov/Documents/mongo_utils/_opam/lib/base/caml -I /Users/denis.greben[...]
# File "linux_ext/src/linux_ext.ml", line 615, characters 17-29:
# 615 | module Timerfd = Null.Timerfd
#                        ^^^^^^^^^^^^
# Error: Unbound module Null
#     ocamlopt core_unix/src/.core_unix.objs/native/core_unix.{cmx,o} (exit 2)
# (cd _build/default && /Users/denis.grebennicov/Documents/abc/_opam/bin/ocamlopt.opt -w -40 -g -I core_unix/src/.core_unix.objs/byte -I core_unix/src/.core_unix.objs/native -I /Users/denis.grebennicov/Documents/mongo_utils/_opam/lib/base -I /Users/denis.grebennicov/Documents/mongo_utils/_opam/lib/base/base_internalhash_types -I /Users/denis.grebennicov/Documents/mongo_utils/_opam/lib/b[...]
# File "core_unix/src/core_unix.ml", line 849, characters 11-23:
# 849 |   type t = Spawn.Pgid.t
#                  ^^^^^^^^^^^^
# Error: Unbound module Spawn.Pgid

File "lock_file_blocking/src/dune", line 9, characters 0-96:
 9 | (rule
10 |  (targets config.h)
11 |  (deps)
12 |  (action
13 |   (bash "cp %{lib:jst-config:config.h} %{targets}")))
(cd _build/default/lock_file_blocking/src && C:\cygwin64\bin\bash.exe -e -u -o pipefail -c "cp C:\Users\sebastien\AppData\Local\opam\sandbox\lib\jst-config\config.h config.h")
cp: cannot stat 'C:UserssebastienAppDataLocalopamsandboxlibjst-configconfig.h': No such file or directory

File "core_unix/src/dune", line 5, characters 45-65:
5 |  (c_names nss_stubs timespec core_unix_stubs core_unix_time_stubs)
                                                 ^^^^^^^^^^^^^^^^^^^^
core_unix_time_stubs.c:57:13: error: implicit declaration of function 'clock_getcpuclockid' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
  int ret = clock_getcpuclockid(pid, &clock);
            ^