opam install depext fails; poss due to tar given a Windows path

[sishtiaq]

1. Start on a clean Windows 10 machine.
2. Run the installer as per instructions: I get OCaml in C:\OCaml; I put cygwin64 in C:\cygwin64.
3. Run 'opam init', OK.
4. Run 'opam install depext'. The command fails while trying to bunzip2 cmdliner. An 'opam install depext --debug' output attached.

Notice that the tar command that unpacks the cmdliner package has a Windows style path. If I type this command (tar xfj c:\cygwin64... ) in a Cygwin shell, it doesn't work (fails with a very similar message of buzip2 complaining that Compressed file ends unexpectedly).

/usr/bin/tar version 1.28; /usr/bin/bunzip2 version 1.0.6.

This is not a reproducible bug. On my Windows 10 laptop, this all runs fine (tar is given a Unix-type path of /home/sishtiaq/.opam/packages.dev/cmdliner.0.9.8/cmdliner-0.9.8.tbz).
I would think this is unlikely to be a bug in the ocaml-installer, more likely in opam or Cygwin. But recording here because of the combination of circumstances to get to this bug,
Possibly related to Issue #40.

opam-install-depext.txt

[msprotz]

For the record, the newer readme at https://github.com/protz/ocaml-installer/wiki covers try to catch this case (most likely due to another tar in the path).

[sishtiaq]

Out of curiousity: which tar should opam be using, then?

[ignacio-gc]

It seems that the tar that comes with cygwin, not other tar. Thanks @msprotz, I forgot to delete msys2 from path. Now I have another error, I'll trying to figure out myself.

Lambda-term installation fails with:

# install: cannot create regular file ~/.opam/system/bin/lambda-term-actions: File exists

[msprotz]

@sishtiaq: opam should be using the tar from cygwin.
@ignaciocaamanio: ocaml/opam#2313

Try manually fixing ~/.opam/system/repositories/default/packages/lambda-term.../files/....install to not install lambda-term-actions twice. I suspect the file is installed once by the Makefile, then a second time by the ....install file, which then fails because of the OPAM issue mentioned above.

[ignacio-gc]

Thanks. After a long time can make it work. In lambda-term.install I delete the two lines where 'lambda-term-actions' occur. Also for utop I have to add .exe to 'utop-full' and 'utop' in utop.install... and had problems with the libs path and utop... I don't know exactly how but eval opam config env was involved... thanks for the help!

[sishtiaq]

@msprotz That means I can't have a Windows machine with "Git for Windows" on it? (VS recommends installing it!)

[ignacio-gc]

I think you can,, just don't install cygwin git, use where git to see the path of the git you are using.

Now I try to install merlin and the install script fails with syntax error near unexpected token...
¿Merlin can be installed?

[ignacio-gc]

I realized that the 64-bit version can not be installed merlin... I'll try with 32 bits.

[msprotz]

@sishtiaq good question; I don't use "git for windows", because it basically re-packages an entire linux set of utilities (bash, perl, and a million other files). I'd be interested in knowing if it's feasible to have the two co-exist (maybe with careful precedence of things in PATH?)

@ignaciocaamanio Merlin doesn't work because the patched version of OPAM that I'm using currently has a bug when forking out external shell commands; I have a newer version of OPAM that I can try to send you by email... contact me privately?

[ignacio-gc]

@msprotz Ok, all this was to use merlin and utop in emacs, so if you have a solution great ! How do I contact you ? There is a way in github or I should post my mail ?

[msprotz]

my email address is on my personal website at jonathan.protzenko.fr