Building Docs for Packages When Depext is Unavailable

[sabine]

Opam plugin "depext" may require upgrading/reinstalling. Reinstall the plugin on the current switch? [Y/n] y
The following actions will be performed:
  - recompile opam-depext 1.2.1-1

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
-> retrieved opam-depext.1.2.1-1  (cached)
-> removed   opam-depext.1.2.1-1
-> installed opam-depext.1.2.1-1
Done.

<><> opam-depext.1.2.1-1 installed successfully <><><><><><><><><><><><><><><><>
=> opam-depext is unnecessary when used with opam >= 2.1. Please use opam install directly instead
# Run eval $(opam env) to update the current shell environment

<><> Carrying on to "opam depext -viy llvm.15.0.7+nnp-2 stdlib-shims.0.3.0 integers.0.7.0 dune-configurator.3.10.0 dune.3.10.0 ctypes.0.21.1 csexp.1.5.2 conf-llvm.15 conf-bash.1 bigarray-compat.1.1.0" 

You are using opam 2.1+, where external dependency handling has been integrated: consider calling opam directly, the 'depext' plugin interface is provided for backwards compatibility only
# Detecting depexts using vars: arch=x86_64, os=linux, os-distribution=debian, os-family=debian
[ERROR] No solution for llvm.15.0.7+nnp-2 & stdlib-shims.0.3.0 & integers.0.7.0 & dune-configurator.3.10.0 & dune.3.10.0 & ctypes.0.21.1 & csexp.1.5.2 & conf-llvm.15 & conf-bash.1 & bigarray-compat.1.1.0:   * Missing dependency:
            - conf-llvm >= 15
            depends on the unavailable system package 'llvm-15-dev'. Use `--no-depexts' to attempt installation anyway, or it is possible that a depext package name in the opam file is incorrect.


Command failed: opam --cli=2.1 list --readonly --external '--resolve=llvm.15.0.7+nnp-2,stdlib-shims.0.3.0,integers.0.7.0,dune-configurator.3.10.0,dune.3.10.0,ctypes.0.21.1,csexp.1.5.2,conf-llvm.15,conf-bash.1,bigarray-compat.1.1.0' returned 20

From https://ocaml.org/p/llvm/latest/doc/index.html

Would it be possible to install a package without the depext just for the purpose of generating documentation?

If not, I think this means we need more images on which to build, so that depexts can be installed.

[kit-ty-kate]

This particular package would work if the distribution used was upgraded though. From a quick scan at the code, it looks like Debian 10 (2 versions out of date) is still being used:

ocaml-docs-ci/src/lib/platform.ml

Line 11 in e971142

let os_version = function Ubuntu -> "20.04" | Fedora -> "33" | Debian -> "10"

[sabine]

Ah ok. Upgrading to the next Debian version sounds fine in that case.

[tmcgilchrist]

Fix in #147

[kit-ty-kate]

the overarching problem is still around as there might be a package that require a specific distribution to be compiled.

[tmcgilchrist]

Docs-CI only considers debian-12 as a distribution to build on. In future we could extend that to different Linux distributions quite easily. Do you have a sense of how often this situation occurs with a package needing a specific Linux distribution?

In general we should extend docs to build more platforms specific packages for MacOS, FreeBSD and Windows? Is there a way to find how many packages are affected from just the opam-repository files?

@sabine we could probably look through the solver failures and classify them into platform failures and other types of failures.