Incorrect message on windows for updating environment vars

[JonasOberhauser]

On windows, I get a message to run eval $(opam env). E.g.:

<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
+- The following actions failed
| - build coq-core 8.19.2
+-
- No changes have been performed
# Run eval $(opam env) to update the current shell environment

If I do, my $PATH is totally messed up and opam is no longer in the path.

Instead, it seems I should be using the command provided in a blog post here:

https://opam.ocaml.org/blog/opam-2-2-0-windows/

On second inspection, It seems that this only happens in my mingw shell, in powershell I get the correct command. But either way running eval $(opam env) in the mingw shell does not produce the correct results.

[rjbou]

Can you share the output of opam env in your mingw shell?

[dra27]

Indeed, if you're running opam from within Cygwin/MSYS2, etc. (i.e. bash or some such) then the command suggested is correct and it is supposed to work!

[JonasOberhauser]

Can you share the output of opam env in your mingw shell?

I can tell you how the output differs from what is there in a working environment: all the paths (including paths unrelated to ocaml) are prefixed with /cygdrive/c/... or /cygdrive/d/..., e.g.,

...:/cygdrive/d/Program Files/Git/usr/bin/core_perl

while my working PATH has it as ...:/usr/bin/core_perl

[kit-ty-kate]

I can tell you how the output differs from what is there in a working environment: all the paths (including paths unrelated to ocaml) are prefixed with /cygdrive/c/... or /cygdrive/d/...

both should be equivalent in a cygwin context so i'm not sure why that would break things. Are you using MSYS2, an existing Cygwin installation or the recommended internal Cygwin installation?

...:/cygdrive/d/Program Files/Git/usr/bin/core_perl

while my working PATH has it as ...:/usr/bin/core_perl

This part is pretty surprising though, are you sure this is verbatim what's in your PATH? If so, opam is introducing the Git for Windows path without a separator (it should at least be ...:/cygdrive/d/Program Files/Git:/usr/bin/core_perl)

[dra27]

I’ve just noticed something similar to this running opam-with-an-internal-Cygwin installation running in a different Cygwin installation - looks like you’re running opam-with-an-internal-Cygwin-installation in Git for Windows Bash (or an MSYS2 installation) and seeing a bigger version of the same problem.

[dra27]

(I also have an idea for a fix…)

[JonasOberhauser]

I can tell you how the output differs from what is there in a working environment: all the paths (including paths unrelated to ocaml) are prefixed with /cygdrive/c/... or /cygdrive/d/...

both should be equivalent in a cygwin context so i'm not sure why that would break things. Are you using MSYS2, an existing Cygwin installation or the recommended internal Cygwin installation?

I am using my git for windows bash.

...:/cygdrive/d/Program Files/Git/usr/bin/core_perl while my working PATH has it as ...:/usr/bin/core_perl

This part is pretty surprising though, are you sure this is verbatim what's in your PATH? If so, opam is introducing the Git for Windows path without a separator (it should at least be ...:/cygdrive/d/Program Files/Git:/usr/bin/core_perl)

Yep