Can't install packages

[Xotchkass]

OS: Windows 10
Freshly installed opam.

$ opam --version
2.3.0

When trying to run

$ opam install ocaml-lsp-server
The following actions will be performed:
=== install 32 packages
  ∗ astring                 0.8.5   [required by ocaml-lsp-server]
  ∗ base                    v0.17.1 [required by ocaml-lsp-server]
  ∗ camlp-streams           5.0.1   [required by ocaml-lsp-server]
  ∗ chrome-trace            3.17.1  [required by ocaml-lsp-server]
  ∗ csexp                   1.5.2   [required by ocaml-lsp-server]
  ∗ dune                    3.17.1  [required by ocaml-lsp-server]
  ∗ dune-build-info         3.17.1  [required by ocaml-lsp-server]
  ∗ dune-configurator       3.17.1  [required by base]
  ∗ dune-rpc                3.17.1  [required by ocaml-lsp-server]
  ∗ dyn                     3.17.1  [required by ocaml-lsp-server]
  ∗ fiber                   3.7.0   [required by ocaml-lsp-server]
  ∗ jsonrpc                 1.21.0  [required by ocaml-lsp-server]
  ∗ lsp                     1.21.0  [required by ocaml-lsp-server]
  ∗ merlin-lib              5.3-502 [required by ocaml-lsp-server]
  ∗ ocaml-lsp-server        1.21.0
  ∗ ocaml_intrinsics_kernel v0.17.1 [required by base]
  ∗ ocamlbuild              0.15.0  [required by astring]
  ∗ ocamlc-loc              3.17.1  [required by ocaml-lsp-server]
  ∗ ocamlfind               1.9.5   [required by astring]
  ∗ ocamlformat-rpc-lib     0.27.0  [required by ocaml-lsp-server]
  ∗ ordering                3.17.1  [required by ocaml-lsp-server]
  ∗ pp                      2.0.0   [required by ocaml-lsp-server]
  ∗ ppx_yojson_conv_lib     v0.17.0 [required by ocaml-lsp-server]
  ∗ re                      1.12.0  [required by ocaml-lsp-server]
  ∗ seq                     base    [required by re]
  ∗ sexplib0                v0.17.0 [required by base]
  ∗ spawn                   v0.17.0 [required by ocaml-lsp-server]
  ∗ stdune                  3.17.1  [required by ocaml-lsp-server]
  ∗ topkg                   1.0.7   [required by astring]
  ∗ uutf                    1.0.3   [required by lsp]
  ∗ xdg                     3.17.1  [required by ocaml-lsp-server]
  ∗ yojson                  2.2.2   [required by ocaml-lsp-server]

Proceed with ∗ 32 installations? [y/n] y

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><>  🐫
⬇ retrieved camlp-streams.5.0.1  (https://opam.ocaml.org/cache)
⬇ retrieved base.v0.17.1  (https://opam.ocaml.org/cache)
⬇ retrieved astring.0.8.5  (https://opam.ocaml.org/cache)
⬇ retrieved csexp.1.5.2  (https://opam.ocaml.org/cache)
⬇ retrieved fiber.3.7.0  (https://opam.ocaml.org/cache)
Processing  8/85: [chrome-trace.3.17.1 + 9 others: extract] [jsonrpc.1.21.0 + 2 others: extract] [merlin-lib.5.3-502: extract]

it gets stuck like this with 0% CPU utilization. I waited for >30min, so it's safe to assume it would continue indefinitely.
Any ideas how to fix?

[kit-ty-kate]

it would mean that your local version of tar is stuck somehow. You can make sure it is that by re-running the command with -vvv and see which command are ran, then look if those processes are still alive using process manager.

Would you be able to send back the last few lines of the log with -vvv to see if the tar command is the right one?

[Xotchkass]

...

+ C:\Windows\system32\tar.exe "xfj" "C:\\Users\\user\\AppData\\Local\\opam\\download-cache\\sha256\\86\\8648a15ae93fe6942999ce36887429a3913b62829c4714e520cc0e7a1c3b9682" "-C" "C:\\Users\\user\\AppData\\Local\\Temp\\opam-13692-290256"
⬇ retrieved fiber.3.7.0  (cached)
Processing  8/85: [chrome-trace.3.17.1 + 9 others: extract] [jsonrpc.1.21.0 + 2 others: extract] [merlin-lib.5.3-502: extract]

[kit-ty-kate]

That's what i thought, it's using the tar binary furnished by Windows instead of the one from Cygwin which is known to cause problems. Are you using the recommended internal cygwin setup or do you have a custom setup? (e.g. msys2 or custom cygwin install)

[Xotchkass]

I use msys2. Thanks for help. Installing msys2 version and reordering $PATH helped with extracting.

[Xotchkass]

Okay, installing tar, flexdll and ocaml-compiler-libs helped. Now just one error left.

[ERROR] The compilation of topkg.1.0.7 failed at "ocaml pkg/pkg.ml build --pkg-name topkg --dev-pkg false".

#=== ERROR while compiling topkg.1.0.7 ========================================#
# context     2.3.0 | win32/x86_64 | ocaml-system.5.2.0 | https://opam.ocaml.org#4d67ef48e6a36b5ba83d930da14d544d46025751
# path        ~\AppData\Local\opam\ocaml-system\.opam-switch\build\topkg.1.0.7
# command     C:\tools\msys64\mingw64\bin\ocaml.exe pkg/pkg.ml build --pkg-name topkg --dev-pkg false
# exit-code   125
# env-file    ~\AppData\Local\opam\log\topkg-4200-7b5352.env
# output-file ~\AppData\Local\opam\log\topkg-4200-7b5352.out
### output ###
# Cannot find file topfind.