Problem installing xs

[hakank]

I tried to install xs on my Linux Ubuntu 18.04 LTS machine but opam give some strange errors

$ opam pin add xs https://github.com/smabie/xs.git
"""
Package xs does not exist, create as a NEW package ? [Y/n] y
xs is now git-pinned to https://github.com/smabie/xs.git

[xs] https://github.com/smabie/xs.git updated
[ERROR] File "/home/hakank/.opam/4.06.0/packages.dev/xs/xs.opam", line 8, character 26-27: parse error.
[WARNING] Errors in opam file from xs source, ignored (fix with 'opam pin edit')

[ERROR] File "/home/hakank/.opam/4.06.0/overlay/xs/opam_", line 8, character 26-27: parse error.
Invalid opam file:
error 1: File does not parse
Errors in /home/hakank/.opam/4.06.0/overlay/xs/opam, retry editing ? [Y/n] n
[ERROR] No valid metadata available.
xs is now unpinned from git https://github.com/smabie/xs.git
"""

The generated file that comes up with the fix command (for editing the file) is this:
"""

This file is generated by dune, edit dune-project instead

opam-version: "2.0"
synopsis: "Xs is a concatenative array language inspired by kdb+/q"
description: """
Xs is a unique concatenative language that aims to match the power
of q with more flexibility and expressiveness. Xs is dynamically
typed with dynamic scoping and puts a strong emphasis on terseness,
beauty, and simplicity."""
maintainer: ["sturm@cryptm.org"]
authors: ["Sturm Mabie"]
license: "Public Domain"
homepage: "https://github.com/smabie/xs"
bug-reports: "https://github.com/smabie/xs/issues"
depends: [
"ocaml" "dune" "core" "angstrom" "res" "ppx_jane" "ppx_inline_test"
]
build: [
["dune" "subst"] {pinned}
[
"dune"
"build"
"-p"
name
"-j"
jobs
"@install"
"@runtest" {with-test}
"@doc" {with-doc}
]
]
dev-repo: "git+https://github.com/smabie/xs.git"
"""

My opam version is 1.2.2.

Do you have any suggestions how to proceed?

[smabie]

You are using a very old opam version and old OCaml. To get a current version of opam:

add-apt-repository ppa:avsm/ppa
apt update
apt install opam

For more info, check out the opam install instructions: https://opam.ocaml.org/doc/Install.html

Right now, I'm using opam 2.0.7, so check with opam --version that it is atleast 2.x. Just to be sure, let's use the optimized version of the latest OCaml release:

opam switch create 4.10.0+flambda 4.10.0+flambda

This creates a new opam switch called '4.10.0+flambda` that's pinned to version 4.10.0+flambda (flambda is the optimizing compiler). Now simply just run the install command again:

opam pin add xs https://github.com/smabie/xs.git

Let me know if this works for you. Thanks for trying out xs!

[hakank]

Ah, I would expect it was an old version. Excellent, it works now.