FreeBSD CI failures

[hannesm]

Dear Madam or Sir,

thanks for providing this CI system. I encounter various failures that are FreeBSD related:

https://ocaml.ci.dev/github/mirage/mirage-crypto/commit/c7c4eb58a6aca2a316b9f1883f02a29e52238768/variant/freebsd-4.14_opam-2.1

/src: (run (cache (opam-archives (target /home/opam/.opam/download-cache)))
           (network host)
           (shell "opam update --depexts && opam install --cli=2.1 --depext-only -y mirage-crypto.dev mirage-crypto-rng.dev mirage-crypto-rng-mirage.dev mirage-crypto-rng-lwt.dev mirage-crypto-rng-async.dev mirage-crypto-pk.dev mirage-crypto-ec.dev $DEPS"))
[WARNING] Unknown update command for bsd, skipping system update


<><> Synchronising pinned packages ><><><><><><><><><><><><><><><><><><><><><><>
[mirage-crypto.dev] synchronised (no changes)
[mirage-crypto-pk.dev] synchronised (no changes)
[mirage-crypto-ec.dev] synchronised (no changes)
[mirage-crypto-rng.dev] synchronised (no changes)
[mirage-crypto-rng-async.dev] synchronised (no changes)
[mirage-crypto-rng-lwt.dev] synchronised (no changes)
[mirage-crypto-rng-mirage.dev] synchronised (no changes)


[NOTE] Package ocaml-options-vanilla is already installed (current version is 1).
[NOTE] Package ocaml-config is already installed (current version is 2).
[NOTE] Package base-unix is already installed (current version is base).
[NOTE] Package base-threads is already installed (current version is base).
[NOTE] Package base-bigarray is already installed (current version is base).
[ERROR] Package conflict!
  * No agreement on the version of ocaml-base-compiler:
    - ocaml-base-compiler = 4.14.1
    - (invariant) → ocaml-base-compiler = 4.14.2
    You can temporarily relax the switch invariant with `--update-invariant'


2024-03-19 11:00.40 ---> saved as "755a7dbe7b13fdf96fc96d0b86389d708dda8d9c5fbbbcaa6e0872edf87314c1"


/src: (run (cache (opam-archives (target /home/opam/.opam/download-cache)))
           (network host)
           (shell "opam install $DEPS"))
[NOTE] Package ocaml-options-vanilla is already installed (current version is 1).
[NOTE] Package ocaml-config is already installed (current version is 2).
[NOTE] Package base-unix is already installed (current version is base).
[NOTE] Package base-threads is already installed (current version is base).
[NOTE] Package base-bigarray is already installed (current version is base).
[ERROR] Package conflict!
  * No agreement on the version of ocaml-base-compiler:
    - ocaml-base-compiler = 4.14.1
    - (invariant) → ocaml-base-compiler = 4.14.2
    You can temporarily relax the switch invariant with `--update-invariant'


No solution found, exiting
jail: /usr/bin/su -l opam -c cd '/src' && env OCAMLCI='true' CI='true' DEPS='alcotest.1.7.0 astring.0.8.5 async.v0.16.0 async_kernel.v0.16.0 async_rpc_kernel.v0.16.0 async_unix.v0.16.0 base.v0.16.3 base-bigarray.base base-bytes.base base-threads.base base-unix.base base_bigstring.v0.16.0 base_quickcheck.v0.16.0 bin_prot.v0.16.0 cmdliner.1.2.0 conf-bash.1 conf-gmp.4 conf-gmp-powm-sec.3 core.v0.16.2 core_kernel.v0.16.0 core_unix.v0.16.0 cppo.1.6.9 csexp.1.5.2 cstruct.6.2.0 digestif.1.2.0 domain-name.0.4.0 dune.3.14.2 dune-configurator.3.14.2 duration.0.2.1 eqaf.0.9 expect_test_helpers_core.v0.16.0 fieldslib.v0.16.0 fmt.0.9.0 functoria-runtime.4.4.2 hex.1.5.0 int_repr.v0.16.0 ipaddr.5.5.0 jane-street-headers.v0.16.0 jst-config.v0.16.0 logs.0.7.0 lwt.5.7.0 macaddr.5.5.0 mirage-clock.4.2.0 mirage-clock-unix.4.2.0 mirage-runtime.4.4.2 mirage-time.3.0.0 mirage-time-unix.3.0.0 mirage-unix.5.0.1 mtime.2.0.0 num.1.5 ocaml.4.14.1 ocaml-base-compiler.4.14.1 ocaml-compiler-libs.v0.12.4 ocaml-config.2 ocaml-options-vanilla.1 ocaml-syntax-shims.1.0.0 ocaml_intrinsics.v0.16.1 ocamlbuild.0.14.3 ocamlfind.1.9.6 ocplib-endian.1.2 ounit2.2.2.7 parsexp.v0.16.0 ppx_assert.v0.16.0 ppx_base.v0.16.0 ppx_bench.v0.16.0 ppx_bin_prot.v0.16.0 ppx_cold.v0.16.0 ppx_compare.v0.16.0 ppx_custom_printf.v0.16.0 ppx_derivers.1.2.1 ppx_deriving.5.2.1 ppx_deriving_yojson.3.7.0 ppx_disable_unused_warnings.v0.16.0 ppx_enumerate.v0.16.0 ppx_expect.v0.16.0 ppx_fields_conv.v0.16.0 ppx_fixed_literal.v0.16.0 ppx_globalize.v0.16.0 ppx_hash.v0.16.0 ppx_here.v0.16.0 ppx_ignore_instrumentation.v0.16.0 ppx_inline_test.v0.16.1 ppx_jane.v0.16.0 ppx_let.v0.16.0 ppx_log.v0.16.0 ppx_module_timer.v0.16.0 ppx_optcomp.v0.16.0 ppx_optional.v0.16.0 ppx_pipebang.v0.16.0 ppx_sexp_conv.v0.16.0 ppx_sexp_message.v0.16.0 ppx_sexp_value.v0.16.0 ppx_stable.v0.16.0 ppx_stable_witness.v0.16.0 ppx_string.v0.16.0 ppx_tydi.v0.16.0 ppx_typerep_conv.v0.16.0 ppx_variants_conv.v0.16.0 ppxlib.0.32.0 protocol_version_header.v0.16.0 randomconv.0.2.0 re.1.11.0 result.1.5 seq.base sexp_pretty.v0.16.0 sexplib.v0.16.0 sexplib0.v0.16.0 spawn.v0.15.1 splittable_random.v0.16.0 stdio.v0.16.0 stdlib-shims.0.3.0 textutils.v0.16.0 textutils_kernel.v0.16.0 time_now.v0.16.0 timezone.v0.16.0 topkg.1.0.7 typerep.v0.16.0 uutf.1.0.3 variantslib.v0.16.0 yojson.2.1.2 zarith.1.13' OPAMCOLOR='always' CLICOLOR_FORCE='1' '/usr/bin/env' 'bash' '-c' 'opam install $DEPS': failed
"jail" "-c" "name=obuilder_34190_4365" "mount.fstab=/tmp/obuilder-jail-8d9ebd/fstab" "mount.devfs" "path=/obuilder/result/a7bab9fdd737b5a3e6047927ca9e67db482d7c9f392afe8102a83b6f4dc48afe/rootfs" "host=inherit" "ip6=inherit" "ip4=inherit" "command=/usr/bin/su" "-l" "opam" "-c" "cd '/src' && env OCAMLCI='true' CI='true' DEPS='alcotest.1.7.0 astring.0.8.5 async.v0.16.0 async_kernel.v0.16.0 async_rpc_kernel.v0.16.0 async_unix.v0.16.0 base.v0.16.3 base-bigarray.base base-bytes.base base-threads.base base-unix.base base_bigstring.v0.16.0 base_quickcheck.v0.16.0 bin_prot.v0.16.0 cmdliner.1.2.0 conf-bash.1 conf-gmp.4 conf-gmp-powm-sec.3 core.v0.16.2 core_kernel.v0.16.0 core_unix.v0.16.0 cppo.1.6.9 csexp.1.5.2 cstruct.6.2.0 digestif.1.2.0 domain-name.0.4.0 dune.3.14.2 dune-configurator.3.14.2 duration.0.2.1 eqaf.0.9 expect_test_helpers_core.v0.16.0 fieldslib.v0.16.0 fmt.0.9.0 functoria-runtime.4.4.2 hex.1.5.0 int_repr.v0.16.0 ipaddr.5.5.0 jane-street-headers.v0.16.0 jst-config.v0.16.0 logs.0.7.0 lwt.5.7.0 macaddr.5.5.0 mirage-clock.4.2.0 mirage-clock-unix.4.2.0 mirage-runtime.4.4.2 mirage-time.3.0.0 mirage-time-unix.3.0.0 mirage-unix.5.0.1 mtime.2.0.0 num.1.5 ocaml.4.14.1 ocaml-base-compiler.4.14.1 ocaml-compiler-libs.v0.12.4 ocaml-config.2 ocaml-options-vanilla.1 ocaml-syntax-shims.1.0.0 ocaml_intrinsics.v0.16.1 ocamlbuild.0.14.3 ocamlfind.1.9.6 ocplib-endian.1.2 ounit2.2.2.7 parsexp.v0.16.0 ppx_assert.v0.16.0 ppx_base.v0.16.0 ppx_bench.v0.16.0 ppx_bin_prot.v0.16.0 ppx_cold.v0.16.0 ppx_compare.v0.16.0 ppx_custom_printf.v0.16.0 ppx_derivers.1.2.1 ppx_deriving.5.2.1 ppx_deriving_yojson.3.7.0 ppx_disable_unused_warnings.v0.16.0 ppx_enumerate.v0.16.0 ppx_expect.v0.16.0 ppx_fields_conv.v0.16.0 ppx_fixed_literal.v0.16.0 ppx_globalize.v0.16.0 ppx_hash.v0.16.0 ppx_here.v0.16.0 ppx_ignore_instrumentation.v0.16.0 ppx_inline_test.v0.16.1 ppx_jane.v0.16.0 ppx_let.v0.16.0 ppx_log.v0.16.0 ppx_module_timer.v0.16.0 ppx_optcomp.v0.16.0 ppx_optional.v0.16.0 ppx_pipebang.v0.16.0 ppx_sexp_conv.v0.16.0 ppx_sexp_message.v0.16.0 ppx_sexp_value.v0.16.0 ppx_stable.v0.16.0 ppx_stable_witness.v0.16.0 ppx_string.v0.16.0 ppx_tydi.v0.16.0 ppx_typerep_conv.v0.16.0 ppx_variants_conv.v0.16.0 ppxlib.0.32.0 protocol_version_header.v0.16.0 randomconv.0.2.0 re.1.11.0 result.1.5 seq.base sexp_pretty.v0.16.0 sexplib.v0.16.0 sexplib0.v0.16.0 spawn.v0.15.1 splittable_random.v0.16.0 stdio.v0.16.0 stdlib-shims.0.3.0 textutils.v0.16.0 textutils_kernel.v0.16.0 time_now.v0.16.0 timezone.v0.16.0 topkg.1.0.7 typerep.v0.16.0 uutf.1.0.3 variantslib.v0.16.0 yojson.2.1.2 zarith.1.13' OPAMCOLOR='always' CLICOLOR_FORCE='1' '/usr/bin/env' 'bash' '-c' 'opam install $DEPS'" failed with exit status 1
2024-03-19 11:04.44: Job failed: Failed: Build failed

And https://ocaml.ci.dev/github/mirage/mirage-crypto/commit/c7c4eb58a6aca2a316b9f1883f02a29e52238768/variant/freebsd-5.1_opam-2.1

File "tests/dune", line 35, characters 7-36:
35 |  (name test_entropy_collection_async)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
(cd _build/default && /home/opam/.opam/5.1.1/bin/ocamlopt.opt -w @[email protected]@30..39@[email protected]@[email protected] -strict-sequence -strict-formats -short-paths -keep-locs -g -o tests/test_entropy_collection_async.exe /home/opam/.opam/5.1.1/lib/base/base_internalhash_types/base_internalhash_types.cmxa -I /home/opam/.opam/5.1.1/lib/base/base_internalhash_types /home/opam/.opam/5.1.1/lib/base/caml/caml.cmxa /home/opam/.opam/5.1.1/lib/sexplib0/sexplib0.cmxa /home/opam/.opam/5.1.1/lib/base/shadow_stdlib/shadow_stdlib.cmxa /home/opam/.opam/5.1.1/lib/base/base.cmxa -I /home/opam/.opam/5.1.1/lib/base /home/opam/.opam/5.1.1/lib/ppx_sexp_conv/runtime-lib/ppx_sexp_conv_lib.cmxa /home/opam/.opam/5.1.1/lib/ppx_compare/runtime-lib/ppx_compare_lib.cmxa /home/opam/.opam/5.1.1/lib/ppx_enumerate/runtime-lib/ppx_enumerate_lib.cmxa /home/opam/.opam/5.1.1/lib/ppx_hash/runtime-lib/ppx_hash_lib.cmxa /home/opam/.opam/5.1.1/lib/ppx_here/runtime-lib/ppx_here_lib.cmxa /home/opam/.opam/5.1.1/lib/ppx_assert/runtime-lib/ppx_assert_lib.cmxa /home/opam/.opam/5.1.1/lib/ppx_bench/runtime-lib/ppx_bench_lib.cmxa /home/opam/.opam/5.1.1/lib/base/md5/md5_lib.cmxa /home/opam/.opam/5.1.1/lib/fieldslib/fieldslib.cmxa /home/opam/.opam/5.1.1/lib/variantslib/variantslib.cmxa /home/opam/.opam/5.1.1/lib/bin_prot/shape/bin_shape.cmxa /home/opam/.opam/5.1.1/lib/ppx_stable_witness/stable_witness/stable_witness.cmxa /home/opam/.opam/5.1.1/lib/bin_prot/bin_prot.cmxa -I /home/opam/.opam/5.1.1/lib/bin_prot /home/opam/.opam/5.1.1/lib/ppx_inline_test/config/inline_test_config.cmxa /home/opam/.opam/5.1.1/lib/jane-street-headers/jane_street_headers.cmxa /home/opam/.opam/5.1.1/lib/time_now/time_now.cmxa -I /home/opam/.opam/5.1.1/lib/time_now /home/opam/.opam/5.1.1/lib/ppx_inline_test/runtime-lib/ppx_inline_test_lib.cmxa /home/opam/.opam/5.1.1/lib/stdio/stdio.cmxa /home/opam/.opam/5.1.1/lib/ppx_module_timer/runtime/ppx_module_timer_runtime.cmxa /home/opam/.opam/5.1.1/lib/ppx_stable_witness/runtime/ppx_stable_witness_runtime.cmxa /home/opam/.opam/5.1.1/lib/typerep/typerep_lib.cmxa /home/opam/.opam/5.1.1/lib/ppx_expect/common/expect_test_common.cmxa /home/opam/.opam/5.1.1/lib/ppx_expect/config_types/expect_test_config_types.cmxa /home/opam/.opam/5.1.1/lib/ppx_expect/collector/expect_test_collector.cmxa -I /home/opam/.opam/5.1.1/lib/ppx_expect/collector /home/opam/.opam/5.1.1/lib/ppx_expect/config/expect_test_config.cmxa /home/opam/.opam/5.1.1/lib/parsexp/parsexp.cmxa /home/opam/.opam/5.1.1/lib/sexplib/sexplib.cmxa /home/opam/.opam/5.1.1/lib/ppx_log/types/ppx_log_types.cmxa /home/opam/.opam/5.1.1/lib/splittable_random/splittable_random.cmxa /home/opam/.opam/5.1.1/lib/base_quickcheck/base_quickcheck.cmxa /home/opam/.opam/5.1.1/lib/base_quickcheck/ppx_quickcheck/runtime/ppx_quickcheck_runtime.cmxa /home/opam/.opam/5.1.1/lib/int_repr/int_repr.cmxa /home/opam/.opam/5.1.1/lib/base_bigstring/base_bigstring.cmxa -I /home/opam/.opam/5.1.1/lib/base_bigstring /home/opam/.opam/5.1.1/lib/core/base_for_tests/base_for_tests.cmxa /home/opam/.opam/5.1.1/lib/core/filename_base/filename_base.cmxa /home/opam/.opam/5.1.1/lib/core/univ_map/univ_map.cmxa /home/opam/.opam/5.1.1/lib/core/command/command.cmxa /home/opam/.opam/5.1.1/lib/core/heap_block/heap_block.cmxa -I /home/opam/.opam/5.1.1/lib/core/heap_block /home/opam/.opam/5.1.1/lib/core/validate/validate.cmxa /home/opam/.opam/5.1.1/lib/core/core.cmxa -I /home/opam/.opam/5.1.1/lib/core /home/opam/.opam/5.1.1/lib/core_kernel/thread_pool_cpu_affinity/thread_pool_cpu_affinity.cmxa /home/opam/.opam/5.1.1/lib/core_kernel/tuple_pool/tuple_pool.cmxa /home/opam/.opam/5.1.1/lib/core_kernel/timing_wheel/timing_wheel.cmxa /home/opam/.opam/5.1.1/lib/async_kernel/config/async_kernel_config.cmxa /home/opam/.opam/5.1.1/lib/core_kernel/moption/moption.cmxa /home/opam/.opam/5.1.1/lib/core_kernel/pairing_heap/pairing_heap.cmxa /home/opam/.opam/5.1.1/lib/core_kernel/sexp_hidden_in_test/sexp_hidden_in_test.cmxa /home/opam/.opam/5.1.1/lib/core_kernel/uopt/uopt.cmxa /home/opam/.opam/5.1.1/lib/core_kernel/thread_safe_queue/thread_safe_queue.cmxa /home/opam/.opam/5.1.1/lib/async_kernel/async_kernel.cmxa /home/opam/.opam/5.1.1/lib/ocaml/unix/unix.cmxa /home/opam/.opam/5.1.1/lib/ocaml/threads/threads.cmxa /home/opam/.opam/5.1.1/lib/core_kernel/caml_threads/caml_threads.cmxa /home/opam/.opam/5.1.1/lib/core_unix/error_checking_mutex/error_checking_mutex.cmxa -I /home/opam/.opam/5.1.1/lib/core_unix/error_checking_mutex /home/opam/.opam/5.1.1/lib/core_kernel/flags/flags.cmxa /home/opam/.opam/5.1.1/lib/sexplib/unix/sexplib_unix.cmxa /home/opam/.opam/5.1.1/lib/core_kernel/caml_unix/caml_unix.cmxa /home/opam/.opam/5.1.1/lib/core_unix/signal_unix/signal_unix.cmxa -I /home/opam/.opam/5.1.1/lib/core_unix/signal_unix /home/opam/.opam/5.1.1/lib/spawn/spawn.cmxa -I /home/opam/.opam/5.1.1/lib/spawn /home/opam/.opam/5.1.1/lib/core_unix/core_unix.cmxa -I /home/opam/.opam/5.1.1/lib/core_unix /home/opam/.opam/5.1.1/lib/core_unix/ocaml_c_utils/ocaml_c_utils.cmxa -I /home/opam/.opam/5.1.1/lib/core_unix/ocaml_c_utils /home/opam/.opam/5.1.1/lib/core_unix/bigstring_unix/bigstring_unix.cmxa -I /home/opam/.opam/5.1.1/lib/core_unix/bigstring_unix /home/opam/.opam/5.1.1/lib/core_kernel/bounded_int_table/bounded_int_table.cmxa /home/opam/.opam/5.1.1/lib/async_kernel/eager_deferred/eager_deferred.cmxa /home/opam/.opam/5.1.1/lib/core_unix/sys_unix/sys_unix.cmxa -I /home/opam/.opam/5.1.1/lib/core_unix/sys_unix /home/opam/.opam/5.1.1/lib/core_unix/filename_unix/filename_unix.cmxa -I /home/opam/.opam/5.1.1/lib/core_unix/filename_unix /home/opam/.opam/5.1.1/lib/core_kernel/iobuf/iobuf.cmxa /home/opam/.opam/5.1.1/lib/core_unix/iobuf_unix/iobuf_unix.cmxa -I /home/opam/.opam/5.1.1/lib/core_unix/iobuf_unix /home/opam/.opam/5.1.1/lib/core_unix/core_thread/core_thread.cmxa -I /home/opam/.opam/5.1.1/lib/core_unix/core_thread /home/opam/.opam/5.1.1/lib/core_unix/nano_mutex/nano_mutex.cmxa /home/opam/.opam/5.1.1/lib/async_kernel/read_write_pair/read_write_pair.cmxa /home/opam/.opam/5.1.1/lib/core_unix/squeue/squeue.cmxa /home/opam/.opam/5.1.1/lib/timezone/timezone.cmxa /home/opam/.opam/5.1.1/lib/core_unix/time_float_unix/time_float_unix.cmxa /home/opam/.opam/5.1.1/lib/core_unix/time_ns_unix/time_ns_unix.cmxa /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.cmxa -I /home/opam/.opam/5.1.1/lib/core_unix/linux_ext /home/opam/.opam/5.1.1/lib/async_unix/thread_safe_ivar/thread_safe_ivar.cmxa /home/opam/.opam/5.1.1/lib/async_unix/thread_pool/thread_pool.cmxa /home/opam/.opam/5.1.1/lib/ocaml_intrinsics/ocaml_intrinsics.cmxa -I /home/opam/.opam/5.1.1/lib/ocaml_intrinsics /home/opam/.opam/5.1.1/lib/core_unix/time_stamp_counter/time_stamp_counter.cmxa -I /home/opam/.opam/5.1.1/lib/core_unix/time_stamp_counter /home/opam/.opam/5.1.1/lib/core_kernel/uuid/uuid.cmxa /home/opam/.opam/5.1.1/lib/core_unix/uuid/uuid_unix.cmxa /home/opam/.opam/5.1.1/lib/async_unix/async_unix.cmxa -I /home/opam/.opam/5.1.1/lib/async_unix /home/opam/.opam/5.1.1/lib/async/async_command/async_command.cmxa /home/opam/.opam/5.1.1/lib/async/async_quickcheck/async_quickcheck.cmxa /home/opam/.opam/5.1.1/lib/core_kernel/bus/bus.cmxa /home/opam/.opam/5.1.1/lib/async_kernel/persistent_connection_kernel/persistent_connection_kernel.cmxa /home/opam/.opam/5.1.1/lib/protocol_version_header/protocol_version_header.cmxa /home/opam/.opam/5.1.1/lib/async_rpc_kernel/async_rpc_kernel.cmxa /home/opam/.opam/5.1.1/lib/async/async_rpc/async_rpc.cmxa -I /home/opam/.opam/5.1.1/lib/async/async_rpc /home/opam/.opam/5.1.1/lib/async/async.cmxa /home/opam/.opam/5.1.1/lib/cstruct/cstruct.cmxa -I /home/opam/.opam/5.1.1/lib/cstruct /home/opam/.opam/5.1.1/lib/eqaf/eqaf.cmxa /home/opam/.opam/5.1.1/lib/eqaf/bigstring/eqaf_bigstring.cmxa /home/opam/.opam/5.1.1/lib/eqaf/cstruct/eqaf_cstruct.cmxa src/mirage_crypto.cmxa -I src /home/opam/.opam/5.1.1/lib/digestif/c/digestif_c.cmxa -I /home/opam/.opam/5.1.1/lib/digestif/c rng/mirage_crypto_rng.cmxa /home/opam/.opam/5.1.1/lib/logs/logs.cmxa rng/unix/mirage_crypto_rng_unix.cmxa -I rng/unix rng/async/mirage_crypto_rng_async.cmxa tests/.test_entropy_collection_async.eobjs/native/dune__exe__Test_entropy_collection_async.cmx)
ld: error: undefined symbol: core_linux_timerfd_create
>>> referenced by linux_ext.o:(.text+0x3B6D) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a
>>> referenced by linux_ext.o:(.data+0x3528) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a


ld: error: undefined symbol: core_linux_timerfd_settime
>>> referenced by linux_ext.o:(.text+0x3DEA) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a
>>> referenced by linux_ext.o:(.text+0x4128) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a
>>> referenced by linux_ext.o:(.data+0x3520) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a


ld: error: undefined symbol: core_linux_timerfd_gettime
>>> referenced by linux_ext.o:(.text+0x408A) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a
>>> referenced by linux_ext.o:(.data+0x3518) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a


ld: error: undefined symbol: core_linux_timerfd_CLOCK_REALTIME
>>> referenced by linux_ext.o:(.text+0x98A4) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a
>>> referenced by linux_ext.o:(.data+0x3548) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a


ld: error: undefined symbol: core_linux_timerfd_CLOCK_MONOTONIC
>>> referenced by linux_ext.o:(.text+0x98BA) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a
>>> referenced by linux_ext.o:(.data+0x3540) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a


ld: error: undefined symbol: core_linux_timerfd_TFD_NONBLOCK
>>> referenced by linux_ext.o:(.text+0x9977) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a
>>> referenced by linux_ext.o:(.data+0x3538) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a


ld: error: undefined symbol: core_linux_timerfd_TFD_CLOEXEC
>>> referenced by linux_ext.o:(.text+0x998C) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a
>>> referenced by linux_ext.o:(.data+0x3530) in archive /home/opam/.opam/5.1.1/lib/core_unix/linux_ext/linux_ext.a
cc: error: linker command failed with exit code 1 (use -v to see invocation)
File "caml_startup", line 1:
Error: Error during linking (exit code 1)