#=== ERROR while compiling dune.3.0.3 =========================================#
# context              2.2.0~alpha~dev | cygwin/x86_64 | ocaml-system.4.13.1 | git+https://github.com/ocaml/opam-repository.git#589783b06b2ae581b9393ec4d1bf83b28cdf6d71
# path                 ~/.opam/default/.opam-switch/build/dune.3.0.3
# command              /cygdrive/d/Cache/ocaml-local/bin/ocaml bootstrap.ml -j 1
# exit-code            2
# env-file             ~/.opam/log/dune-262-5ac933.env
# output-file          ~/.opam/log/dune-262-5ac933.out
### output ###
# ocamlc -output-complete-exe -w -24 -g -o .duneboot.exe -I boot unix.cma boot/libs.ml boot/duneboot.ml
# ./.duneboot.exe -j 1
# cd _boot && /cygdrive/d/Cache/ocaml-local/bin/ocamlopt.opt -o ../dune.exe -g -I +threads unix.cmxa threads.cmxa -no-alias-deps -w -49-6 readdir.c wait3_stubs.c fcntl_stubs.c spawn_stubs.c fsevents_stubs.c inotify_stubs.c pthread_chdir_stubs.c -args mods_list
# vendor/spawn/src/spawn_stubs.c:32:10: fatal error: sys/syscall.h: No such file or directory
# compilation terminated.