Opam solver timeout

[vitoyucepi]

Summary

I've encountered issues with the opam install failing due to a resolve timeout error. I'm uncertain where to report this problem, but I'll try my best.

Try to specify a simpler request, use a different solver, or increase the allowed time by setting OPAMSOLVERTIMEOUT to a bigger value (currently, it is set to 60.0 seconds).

Details

I've observed that my containers sometimes fail to build due to a timeout error. Here are some specific instances:

• On June 16th, the solver execution time was approximately 15 seconds.
• On July 22nd, it was around 30 seconds.
• On August 4th, the execution time increased further to about 50 seconds.

I've made a demo repository to test this problem using the GitHub actions.
https://github.com/vitoyucepi/opam-issue-6137
https://github.com/vitoyucepi/opam-issue-6137/actions/runs/10234070897/job/28313089171

You can test it locally by building the container image

FROM ocaml/opam:ubuntu-24.04-ocaml-4.14

ARG DEBIAN_FRONTEND=noninteractive

RUN set -eux; \
      sudo apt-get update; \
      sudo apt-get install --no-install-recommends -y pkg-config libavcodec-dev libavdevice-dev libavfilter-dev libavformat-dev libavutil-dev libswresample-dev libswscale-dev;
RUN opam install ffmpeg prometheus-app

[kit-ty-kate]

The ocaml/opam docker images uses opam 2.0 which is 6 years old and is known to have solver timeout issues.
In my opinion, any use of this image should start with something such as:

RUN sudo ln -f /usr/bin/opam-2.2 /usr/bin/opam
RUN opam init --reinit -n

The upstream issue is tracked in ocurrent/docker-base-images#132
For the remaining few timeouts that can still be happening in master/2.2, these are tracked in #3447

[kit-ty-kate]

ah that's an error to report in opam-repository, a package itself is failing, but not because of the solver. This should also probably be reported upstream: https://github.com/savonet/liquidsoap/issues, the author should probably be able to help you

[vitoyucepi]

Thanks @kit-ty-kate.

[vitoyucepi]

By the way, here's the solver comparison for prometheus-app.

default

=== install 66 packages
  - install angstrom            0.16.0  [required by uri]
  - install asetmap             0.8.1   [required by prometheus-app]
  - install asn1-combinators    0.2.6   [required by x509]
  - install astring             0.8.5   [required by prometheus-app]
  - install base                v0.16.3 [required by ppx_sexp_conv]
  - install base-bytes          base    [required by cohttp]
  - install base64              3.5.1   [required by cohttp]
  - install bigstringaf         0.10.0  [required by angstrom]
  - install bos                 0.2.1   [required by ca-certs]
  - install ca-certs            0.2.3   [required by conduit-lwt-unix]
  - install cmdliner            1.3.0   [required by prometheus-app]
  - install cohttp              5.3.1   [required by cohttp-lwt]
  - install cohttp-lwt          5.3.0   [required by prometheus-app]
  - install cohttp-lwt-unix     5.3.0   [required by prometheus-app]
  - install conduit             6.2.3   [required by conduit-lwt]
  - install conduit-lwt         6.2.3   [required by cohttp-lwt-unix]
  - install conduit-lwt-unix    6.2.3   [required by cohttp-lwt-unix]
  - install conf-bash           1       [required by base]
  - install conf-gmp            4       [required by zarith, conf-gmp-powm-sec]
  - install conf-gmp-powm-sec   3       [required by mirage-crypto-pk]
  - install cppo                1.6.9   [required by lwt]
  - install cstruct             6.2.0   [required by mirage-crypto, x509]
  - install domain-name         0.4.0   [required by ipaddr, x509]
  - install duration            0.2.1   [required by mirage-crypto-rng]
  - install eqaf                0.9     [required by mirage-crypto]
  - install fmt                 0.9.0   [required by prometheus-app]
  - install fpath               0.7.3   [required by ca-certs]
  - install gmap                0.3.0   [required by x509]
  - install ipaddr              5.6.0   [required by conduit-lwt-unix]
  - install ipaddr-sexp         5.6.0   [required by conduit-lwt-unix]
  - install jsonm               1.0.2   [required by cohttp]
  - install logs                0.7.0   [required by prometheus-app]
  - install lwt                 5.7.0   [required by prometheus-app]
  - install macaddr             5.6.0   [required by ipaddr]
  - install magic-mime          1.3.1   [required by cohttp-lwt-unix]
  - install mirage-crypto       0.11.3  [required by ca-certs]
  - install mirage-crypto-ec    0.11.3  [required by x509]
  - install mirage-crypto-pk    0.11.3  [required by x509]
  - install mirage-crypto-rng   0.11.3  [required by x509]
  - install num                 1.5-1   [required by sexplib]
  - install ocaml-compiler-libs v0.12.4 [required by ppxlib]
  - install ocaml-syntax-shims  1.0.0   [required by angstrom]
  - install ocamlbuild          0.15.0  [required by asetmap, astring]
  - install ocamlfind           1.9.6   [required by asetmap, astring]
  - install ocplib-endian       1.2     [required by lwt]
  - install parsexp             v0.16.0 [required by sexplib]
  - install pbkdf               1.2.0   [required by x509]
  - install ppx_derivers        1.2.1   [required by ppxlib]
  - install ppx_sexp_conv       v0.16.0 [required by cohttp-lwt, cohttp-lwt-unix]
  - install ppxlib              0.33.0  [required by ppx_sexp_conv]
  - install prometheus          1.2     [required by prometheus-app]
  - install prometheus-app      1.2
  - install ptime               1.1.0   [required by ca-certs]
  - install re                  1.11.0  [required by prometheus-app]
  - install rresult             0.7.0   [required by bos]
  - install seq                 base    [required by re]
  - install sexplib             v0.16.0 [required by conduit-lwt]
  - install sexplib0            v0.16.0 [required by cohttp-lwt]
  - install stdlib-shims        0.3.0   [required by ppxlib]
  - install stringext           1.6.0   [required by cohttp]
  - install topkg               1.0.7   [required by asetmap, astring]
  - install uri                 4.4.0   [required by cohttp-lwt]
  - install uri-sexp            4.4.0   [required by cohttp]
  - install uutf                1.0.3   [required by jsonm]
  - install x509                0.16.5  [required by ca-certs]
  - install zarith              1.14    [required by asn1-combinators, mirage-crypto-pk]

builtin-0install

=== install 65 packages
  - install angstrom            0.16.0      [required by uri]
  - install asetmap             0.8.1       [required by prometheus-app]
  - install asn1-combinators    0.2.6       [required by x509]
  - install astring             0.8.5       [required by prometheus-app]
  - install base                v0.16.3     [required by ppx_sexp_conv]
  - install base-bytes          base        [required by ocplib-endian]
  - install base64              3.5.1       [required by cohttp]
  - install bigstringaf         0.10.0      [required by angstrom]
  - install bos                 0.2.1       [required by ca-certs]
  - install ca-certs            0.2.3       [required by conduit-lwt-unix]
  - install cmdliner            1.3.0       [required by prometheus-app]
  - install cohttp              6.0.0~beta2 [required by cohttp-lwt, cohttp-lwt-unix]
  - install cohttp-lwt          6.0.0~beta2 [required by prometheus-app]
  - install cohttp-lwt-unix     6.0.0~beta2 [required by prometheus-app]
  - install conduit             6.2.3       [required by conduit-lwt]
  - install conduit-lwt         6.2.3       [required by cohttp-lwt-unix]
  - install conduit-lwt-unix    6.2.3       [required by cohttp-lwt-unix]
  - install conf-bash           1           [required by base]
  - install conf-gmp            4           [required by zarith, conf-gmp-powm-sec]
  - install conf-gmp-powm-sec   3           [required by mirage-crypto-pk]
  - install cppo                1.6.9       [required by lwt]
  - install cstruct             6.2.0       [required by mirage-crypto, x509]
  - install domain-name         0.4.0       [required by ipaddr, x509]
  - install duration            0.2.1       [required by mirage-crypto-rng]
  - install eqaf                0.9         [required by mirage-crypto]
  - install fmt                 0.9.0       [required by prometheus-app]
  - install fpath               0.7.3       [required by ca-certs]
  - install gmap                0.3.0       [required by x509]
  - install http                6.0.0~beta2 [required by cohttp-lwt, cohttp-lwt-unix]
  - install ipaddr              5.6.0       [required by conduit-lwt-unix]
  - install ipaddr-sexp         5.6.0       [required by conduit-lwt-unix]
  - install logs                0.7.0       [required by prometheus-app]
  - install lwt                 5.7.0       [required by prometheus-app]
  - install macaddr             5.6.0       [required by ipaddr]
  - install magic-mime          1.3.1       [required by cohttp-lwt-unix]
  - install mirage-crypto       0.11.3      [required by ca-certs]
  - install mirage-crypto-ec    0.11.3      [required by x509]
  - install mirage-crypto-pk    0.11.3      [required by x509]
  - install mirage-crypto-rng   0.11.3      [required by x509]
  - install num                 1.5-1       [required by sexplib]
  - install ocaml-compiler-libs v0.12.4     [required by ppxlib]
  - install ocaml-syntax-shims  1.0.0       [required by angstrom]
  - install ocamlbuild          0.15.0      [required by asetmap, astring]
  - install ocamlfind           1.9.6       [required by asetmap, astring]
  - install ocplib-endian       1.2         [required by lwt]
  - install parsexp             v0.16.0     [required by sexplib]
  - install pbkdf               1.2.0       [required by x509]
  - install ppx_derivers        1.2.1       [required by ppxlib]
  - install ppx_sexp_conv       v0.16.0     [required by cohttp-lwt, cohttp-lwt-unix]
  - install ppxlib              0.33.0      [required by ppx_sexp_conv]
  - install prometheus          1.2         [required by prometheus-app]
  - install prometheus-app      1.2
  - install ptime               1.1.0       [required by ca-certs]
  - install re                  1.11.0      [required by prometheus-app]
  - install rresult             0.7.0       [required by bos]
  - install seq                 base        [required by re]
  - install sexplib             v0.16.0     [required by conduit-lwt]
  - install sexplib0            v0.16.0     [required by cohttp-lwt]
  - install stdlib-shims        0.3.0       [required by ppxlib]
  - install stringext           1.6.0       [required by cohttp]
  - install topkg               1.0.7       [required by asetmap, astring]
  - install uri                 4.4.0       [required by cohttp-lwt]
  - install uri-sexp            4.4.0       [required by cohttp]
  - install x509                0.16.5      [required by ca-certs]
  - install zarith              1.14        [required by asn1-combinators, mirage-crypto-pk]

[kit-ty-kate]

ah that difference will be fixed by ocaml-opam/opam-0install-cudf#2
Does it compile if you call:

      opam install --assume-depexts --yes \
        prometheus-liquidsoap \
        liquidsoap-lang \
        liquidsoap-libs \
        liquidsoap-libs-extra \
        liquidsoap-core \
        liquidsoap \
        'cohttp<6' \

it's probably that liquidsoap hasn't been tested with cohttp 6 as it's still a beta but it's definitely still something to report to both as they need a constraint to be added in the opam file

[vitoyucepi]

Everything works fine, but I used opam install prometheus-app 'cohttp<6' instead.