Win32 opam damages PATH environment variable

[db4]

# opam config report
# opam-version      2.0.0
# self-upgrade      no
# system            arch=x86_64 os=win32 os-distribution=win32 os-version=10.0.17134
[ERROR] No switch is currently set. Please use 'opam switch' to set or install a switch
# read-state        OpamStd.OpamSys.Exit(50)

When building a switch with opam create switch Win32 opam.exe (but not the Linux one) reverses list order in the system PATH variable. That leads to many problems. Would be great to fix.

[rjbou]

it seems that you have a problem with your opam installation. No switch is set and the config report errors. Can you check the output of opam env, it should at least contains the OPAM_SWITCH_PREFIX.

On windows, opam doesn't perform any specific operation except forcing uppercase naming.
@dra27, do you confirm?

[db4]

it seems that you have a problem with your opam installation. No switch is set and the config report errors.

Of course it is not set: I'm trying to add the very first switch after

opam init local <private repo address> --bare --no-setup

When building OCaml compiler I see that opam reverses directory order in system PATH and it breaks the build. That's why I filed the issue.

On windows, opam doesn't perform any specific operation except forcing uppercase naming.

Not exactly:

opam/src/core/opamStd.ml

Lines 596 to 617 in f2e8e6d

	let split_path_variable ?(clean=true) =
	if Sys.win32 then fun path ->
	let length = String.length path in
	let rec f acc index current last normal =
	if index = length
	then let current = current ^ String.sub path last (index - last) in
	if current <> "" then current::acc else acc
	else let c = path.[index]
	and next = succ index in
	if c = ';' && normal || c = '"' then
	let current = current ^ String.sub path last (index - last) in
	if c = '"' then
	f acc next current next (not normal)
	else
	let acc = if current = "" then acc else current::acc in
	f acc next "" next true
	else
	f acc next current last normal in
	f [] 0 "" 0 true
	else fun path ->
	let split = if clean then OpamString.split else OpamString.split_delim in
	split path path_sep

At first sight the bug is here.

[dra27]

Windows opam doesn’t yet work...

[dra27]

You are correct about the bug - it’s already part of #3348

[db4]

Windows opam doesn’t yet work...

It's unfortunate. For the time being I use Andreas Hauptmann's opam mingw binary. I'm quite happy with it but once OPAM main repository switched to format 2.0, upgrade of opam binary is inevitable as well. How far is windows opam from being functional? What does and what doesn't work currently?