lwt.5.9.2 doesn't compile anymore on Windows with the Cygwin backend

[kit-ty-kate]

Looks like some assumption about the linker were made that doesn't hold on Cygwin.

#=== ERROR while compiling lwt.5.9.2 ==========================================#
# context              2.5.0~alpha1~dev | cygwin/x86_64 | ocaml-system.4.14.2 | git+https://github.com/ocaml/opam-repository.git#38a1469dbbc69c770e534e26f79c97256a442b71
# path                 ~/.opam/default/.opam-switch/build/lwt.5.9.2
# command              ~/.opam/default/bin/dune build -p lwt -j 3 @install
# exit-code            1
# env-file             ~/.opam/log/lwt-623-ad3ec6.env
# output-file          ~/.opam/log/lwt-623-ad3ec6.out
### output ###
# Usage:
# [...]
# 
# Notes:
# * The -I, -l and -L options do not need to be separated from their argument.
# * An option like /linkXXX is an abbrevation for '-link XXX'.
# * An option like -Wl,-XXX is an abbreviation for '-link -XXX'.
# * FlexDLL's object files are searched by default in the same directory as
#   flexlink, or in the directory given by the environment variable FLEXDIR
#   if it is defined.
# * Extra argument can be passed in the environment variable FLEXLINKFLAGS.
# 
# Homepage: http://alain.frisch.fr/flexdll.html

[raphael-proust]

thanks for the report

it's unclear what the actual issue is, all the notes seem like optional thing or are a little bit ambiguous

is there a more complete output? is there a way to know what the error actually is? (i don't have a windows machine to reproduce)

[kit-ty-kate]

This output comes from a CI. You should be able to reproduce it by adding

          - os: windows-latest
            ocaml-compiler: "4.14"
            ocaml-compiler: "ocaml-variants.4.14.2+options,host-system-msvc"
            libev: false

to your setup-ocaml test matrix

[kit-ty-kate]

if you need a windows machine you can also create a qemu windows environment using the following steps:

https://github.com/ocaml/opam/blob/master/release/windows.md

[kit-ty-kate]

Would you be able to point to the fix?

[kit-ty-kate]

This output comes from a CI. You should be able to reproduce it by adding

          - os: windows-latest
            ocaml-compiler: "4.14"
            ocaml-compiler: "ocaml-variants.4.14.2+options,host-system-msvc"
            libev: false

to your setup-ocaml test matrix

looking above i think i might have replied that thinking i was commenting on #1082 instead of this ticket, so currently i don't think the cygwin backend is tested

[raphael-proust]

ah sorry, I get confused between the different distros of windows…