Running opam env in non-cygwin bash on windows adds /cygdrive prefixes to each entry of PATH

[gridbugs]

I use git bash (inside the "Terminal" program) as my shell when developing ocaml on windows. Here's the output of opam env from a project with a local opam switchh;

$ opam env
OPAM_LAST_ENV='C:\Users\s\AppData\Local\opam\.last-env\env-49af62de39bcff8e1e427bfedbcf0f3f-0'; export OPAM_LAST_ENV;
OPAM_SWITCH_PREFIX='C:\Users\s\src\dune\_opam'; export OPAM_SWITCH_PREFIX;
CAML_LD_LIBRARY_PATH='C:\Users\s\src\dune\_opam\lib\stublibs;C:\Users\s\src\dune\_opam\lib\ocaml\stublibs;C:\Users\s\src\dune\_opam\lib\ocaml'; export CAML_LD_LIBRARY_PATH;
OCAML_TOPLEVEL_PATH='C:\Users\s\src\dune\_opam\lib\toplevel'; export OCAML_TOPLEVEL_PATH;
MANPATH='C:\Program Files\Git\mingw64\local\man;C:\Program Files\Git\mingw64\share\man;C:\Program Files\Git\usr\local\man;C:\Program Files\Git\usr\share\man;C:\Program Files\Git\usr\man;C:\Program Files\Git\share\man:/cygdrive/c/Users/s/src/dune/_opam/man'; export MANPATH;
PATH='/cygdrive/c/Users/s/src/dune/_opam/bin:/usr/x86_64-w64-mingw32/sys-root/mingw/bin:/cygdrive/c/Users/s/bin:/cygdrive/c/Users/s/.cargo/bin:/cygdrive/c/Users/s/.conda/bin:/cygdrive/c/Users/s/.bin:/cygdrive/c/Users/s/.local/bin:/cygdrive/c/Users/s/.local/sbin:/cygdrive/c/Program Files/Git/usr/games:/cygdrive/c/Program Files/Git/usr/local/games:/cygdrive/c/Users/s/bin:/cygdrive/c/Program Files/Git/mingw64/bin:/cygdrive/c/Program Files/Git/usr/local/bin:/cygdrive/c/Program Files/Git/usr/bin:/cygdrive/c/Program Files/Git/usr/bin:/cygdrive/c/Program Files/Git/mingw64/bin:/cygdrive/c/Program Files/Git/usr/bin:/cygdrive/c/Users/s/bin:/cygdrive/c/windows/system32:/cygdrive/c/windows:/cygdrive/c/windows/System32/Wbem:/cygdrive/c/windows/System32/WindowsPowerShell/v1.0:/cygdrive/c/windows/System32/OpenSSH:/cygdrive/c/Program Files/Git/cmd:/cygdrive/c/Program Files/Neovim/bin:/cygdrive/c/Program Files/PowerShell/7:/cygdrive/c/Users/s/.cargo/bin:/cygdrive/c/Users/s/AppData/Local/Programs/opam/bin:/cygdrive/c/Users/s/AppData/Local/Microsoft/WindowsApps:/cygdrive/c/Users/s/AppData/Local/Microsoft/WinGet/Packages/junegunn.fzf_Microsoft.Winget.Source_8wekyb3d8bbwe:/cygdrive/c/Users/s/AppData/Local/Programs/Microsoft VS Code/bin:/cygdrive/c/Users/s/AppData/Local/Microsoft/WinGet/Packages/direnv.direnv_Microsoft.Winget.Source_8wekyb3d8bbwe:/cygdrive/c/Program Files/Git/usr/bin/vendor_perl:/cygdrive/c/Program Files/Git/usr/bin/core_perl'; export PATH;

Note that each element of PATH has /cygdrive prefixed to it despite not being in a cygwin environment. Fortunately there's an easy workaround: I run eval $(opam env | sed 's/\/cygdrive//g') to set up my environment instead.

My opam config report:

$ opam config report
# opam config report
# opam-version         2.3.0
# self-upgrade         no
# system               arch=x86_64 os=win32 os-distribution=cygwin os-version=10.0.22621
# 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                 7
# repositories         1 (http) (default repo at 232a37e8b008dc04381f5e98c16badfc02ea6962)
# pinned               0
# current-switch       C:\Users\s\src\dune
# invariant            ["ocaml-base-compiler" {= "5.1.1"} | "ocaml-system" {= "5.1.1"}]
# compiler-packages    arch-x86_64.1, conf-mingw-w64-gcc-x86_64.1, flexdll.0.43, mingw-w64-shims.0.2.0, ocaml-base-compiler.5.1.1, ocaml-env-mingw64.1, ocaml-options-vanilla.1, system-mingw.1
# mingw-w64-shims:runtime-x86_64 C:\Users\s\AppData\Local\opam\.cygwin\root\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       C:/Users/s/src/dune/_opam/lib/ocaml/stublibs;C:/Users/s/src/dune/_opam/lib/ocaml
# ocaml:preinstalled   false
# ocaml:compiler       5.1.1

[dra27]

I think this is a duplicate of #6134 (although I still need to finish off the idea I'd had)

[dra27]

The core issue is that opam env uses cygpath from the internal installation, but in this case it should be cygpath resolved in PATH (which would cause it to give /c/Users instead of /cygpath/c/Users)