opam depext integration

[rjbou]

This issue concerns ongoing work of opam-depext intergation into opam itself: as a built-in command and as an install option. see #3975 (comment) for more details

Until the corresponding PR is merged, new depext issues should be expressed in this issue.

[dra27]

@samoht notes that neither opam install --deps . --depext nor opam depext . allow installing local depext packages.

@talex5 observes opam install . --show-actions --deps-only -t | awk '/- install/{print $3}' | xargs opam depext -iy is a workaround.

@avsm notes this should be addressed in the depext merge 🙂

[talex5]

In ocurrent/ocaml-ci#21, @kit-ty-kate notes that this is a better work-around: opam install . --dry-run --deps-only -ty | awk '/-> installed/{print $3}' | xargs opam depext -iy"

[rjbou]

oups, forgot to add a link to this issue. opam depext integration pr is open.

[MisterDA]

I have a problem with the current plugin (have not tested the PR). Sorry if it’s not the right place to report.

I have build OCaml 4.10 and Opam master in Cygwin with MSVC. The build of opam-depext (opam install -y opam-depext) fails because at lines shell/build.sh#74 and shell/build.sh#78 the function print_endline is used, which in this case outputs the dreaded \r\n.
When the build script is executed, it fails with:

sh -ex shell/build.sh
+ ocamlc -I src_ext/lib unix.cma cmdliner.cma -o opam-depext $'depext.ml\r'
don't know what to do with depext.ml
Usage: ocamlc <options> <files>

I’m going to patch shell/build.ml with print_string and \n for now.

Note that even if using ocaml-depext with Cygwin could be tricky (although there’s fdopen/depext-cygwinports) a slightly more modern alternative to Cygwin called MSYS2 uses Arch Linux' pacman package manager which, if I’m not mistaken, is already supported by ocaml-depext. So, there may exist users of ocaml-depext on systems using \r\n as end-of-line.

[rjbou]

PR merged and feature published. Feel free to open other issues when you tests!
Thanks!

[gasche]

I arrived at this issue after trying to find out how to install all external dependencies of the dependencies of the current package in a CI script. Above @talex5 and @kit-ty-kate provide the following command (thanks!):

opam install . --dry-run --deps-only -ty | awk '/-> installed/{print $3}' | xargs opam depext -iy

Questions:

• do we have some idea of when the opam-with-depext-integration is planned to be released?
• what will be the equivalent of this magical command in this world? Will opam install . --deps-only just work (invoke the package-manager with depexts first, and install ocaml packages second), or should we expect to pass a depext-specific argument?

[dra27]

It's in opam 2.1 which we're in the process of moving from beta to release candidate.

In opam 2.1, you won't want to add anything except that you want to answer the package managers requests with yes automatically, so set OPAMDEPEXTYES to 1 (see example in https://github.com/ocurrent/opam-repo-ci/blob/911ea5ba73592c7028f5fa3e87d7b20b3ff5c119/lib/opam_build.ml#L46)

[bobot]

Just to note that the magical command doesn't handles the pin-depends.