opam exec fails with Exec format error on bash scripts in 2.2.1 on Windows

[JasonGross]

Not sure if I should be reporting this here or in https://github.com/ocaml/setup-ocaml/issues/866, so I've reported it in both places.

opam config report (failing version 2.2.1)

# opam config report
# opam-version         2.2.1
# self-upgrade         no
# system               arch=x86_64 os=win32 os-distribution=cygwin os-version=10.0.20348
# solver               builtin-mccs+glpk
# install-criteria     -removed,-count[avoid-version,changed],-count[version-lag,request],-count[version-lag,changed],-count[missing-depexts,changed],-changed
# upgrade-criteria     -removed,-count[avoid-version,changed],-count[version-lag,solution],-count[missing-depexts,changed],-new
# jobs                 3
# repositories         1 (version-controlled)
# pinned               0
# current-switch       D:\a\test\test
# invariant            ocaml-base-compiler = 4.13.1
# compiler-packages    arch-x86_64.1, conf-mingw-w64-gcc-x86_64.1, flexdll.0.43, ocaml-base-compiler.4.13.1, ocaml-env-mingw64.1, ocaml-options-vanilla.1, system-mingw.1
# mingw-w64-shims:runtime-x86_64 D:\cygwin\usr\x86_64-w64-mingw32\sys-root\mingw\bin
# mingw-w64-shims:runtime-i686 
# ocaml:native         true
# ocaml:native-tools   true
# ocaml:native-dynlink true
# ocaml:stubsdir       D:/a/test/test/_opam/lib/ocaml/stublibs;D:/a/test/test/_opam/lib/ocaml
# ocaml:preinstalled   false
# ocaml:compiler       4.13.1

opam config report (succeeding version 2.0.10)

# opam config report
# opam-version      2.0.10 
# self-upgrade      no
# system            arch=x86_64 os=win32 os-distribution=cygwinports os-version=10.0.20348
# solver            builtin-mccs+glpk
# install-criteria  -removed,-count[version-lag,request],-count[version-lag,changed],-changed
# upgrade-criteria  -removed,-count[version-lag,solution],-new
# jobs              4
# repositories      1 (version-controlled)
# pinned            0
# current-switch    D:/a/test/test

opam exec -- ./test.sh
Fatal error: exception C:\hostedtoolcache\windows\opam\2.2.1\x86_64\opam.exe: "create_process" failed on ./test.sh: Exec format error

https://github.com/JasonGross/test/actions/runs/10953434095/job/30413705930

logs_28625471194.zip

Full yml file

name: Example Workflow

on: [push, pull_request]

jobs:
  build:

    runs-on: windows-latest
    name: build
    steps:
    - uses: actions/checkout@v4
      with:
        submodules: recursive
    - uses: ocaml/setup-ocaml@v3
      with:
        ocaml-compiler: 4.13.1
    - run: opam config report
    - run: opam exec -- chmod +x test.sh
    - run: opam exec -- cat test.sh
    - run: opam exec -- ./test.sh


  buildv2:

    runs-on: windows-latest
    name: buildv2
    steps:
    - uses: actions/checkout@v2
      with:
        submodules: recursive
    - uses: ocaml/setup-ocaml@v2
      with:
        ocaml-compiler: 4.13.1
    - run: opam config report
    - run: opam exec -- chmod +x test.sh
    - run: opam exec -- cat test.sh
    - run: opam exec -- ./test.sh