2025-08-15 11:59.39: New job: Build using linux-x86_64 in
                                [https://github.com/mirage/mirage-skeleton.git#refs/heads/dev (924fa1b6e311f53d719a3dab1546ea9b43145398)]

OBuilder spec:

((from ocaml/opam:debian-10-ocaml-4.14)
 (user (uid 1000) (gid 1000))
 (workdir /home/opam)
 (run (shell "sudo chown opam:opam /home/opam"))
 (run (shell "sudo ln -f /usr/bin/opam-2.1 /usr/bin/opam && opam update"))
 (run (network host)
      (shell "opam repo add opam https://github.com/ocaml/opam-repository.git#b3b872a94fa79b28ee160b900b3713b3f8ba4dbb"))
 (run (network host)
      (shell "opam repo add mirage-dev https://github.com/mirage/mirage-dev.git#eb114ccf0dd4eeca6b4f06c5c7361c238eeca4fd"))
 (run (cache (download-cache (target /home/opam/.opam/download-cache)))
      (network host)
      (shell "sudo apt-get update && opam install -y \"mirage>=4\""))
 (copy (src .) (dst /src/))
 (env MODE xen)
 (workdir /src/)
 (run (shell "opam exec -- make configure"))
 (env MIRAGE_EXTRA_REPOS opam-overlays:https://github.com/dune-universe/opam-overlays.git#e031bb64e33bf93be963e9a38b28962e6e14381f,mirage-opam-overlays:https://github.com/dune-universe/mirage-opam-overlays.git#797cb363df3ff763c43c8fbec5cd44de2878757e)
 (run (network host)
      (shell "opam exec -- make lock"))
 (run (cache (download-cache (target /home/opam/.opam/download-cache)))
      (network host)
      (shell "sudo apt-get update && opam exec -- make depends"))
 (run (shell "opam monorepo list -l mirage.opam.locked"))
 (run (cache (download-cache (target /home/opam/.opam/download-cache)))
      (network host)
      (shell "opam exec -- make pull"))
 (env DUNE_CACHE enabled)
 (env DUNE_CACHE_TRANSPORT direct)
 (run (cache (dune-build-cache (target /home/opam/.cache/dune)))
      (network host)
      (shell "opam exec -- make build"))
)

2025-08-15 11:59.39: Using cache hint "mirage-ci-skeleton-debian-10-ocaml-4.14"
2025-08-15 11:59.39: Waiting for resource in pool OCluster
2025-08-15 11:59.40: Waiting for worker…
2025-08-15 11:59.41: Got resource from pool OCluster
Building on asteria.caelum.ci.dev
All commits already cached
HEAD is now at 924fa1b defunctorised versions of unikernels (#407)

(from ocaml/opam:debian-10-ocaml-4.14)
2025-08-15 11:59.43 ---> using "feee4396c1d94d93bd2f0711740834a80d493221dd8765a3fda3bfa3da34a3f1" from cache

/: (user (uid 1000) (gid 1000))

/: (workdir /home/opam)

/home/opam: (run (shell "sudo chown opam:opam /home/opam"))
2025-08-15 11:59.43 ---> using "b4aec13d2c0c8862a0b012b7bf45b6c4d9baafb01deec22932d9281a2a3993ed" from cache

/home/opam: (run (shell "sudo ln -f /usr/bin/opam-2.1 /usr/bin/opam && opam update"))
This version of opam requires an update to the layout of /home/opam/.opam from version 2.0 to version 2.1, which can't be reverted.
You may want to back it up before going further.

Continue? [Y/n] y
Format upgrade done.

<><> Updating package repositories ><><><><><><><><><><><><><><><><><><><><><><>
[default] synchronised from file:///home/opam/opam-repository
2025-08-15 11:59.43 ---> using "4b65e2cdab0e73f000c7fd1c66f5d777aef7f109b0fc71798f2edf63b3d5e373" from cache

/home/opam: (run (network host)
                 (shell "opam repo add opam https://github.com/ocaml/opam-repository.git#b3b872a94fa79b28ee160b900b3713b3f8ba4dbb"))
[opam] Initialised
[NOTE] Repository opam has been added to the selections of switch 4.14 only.
       Run `opam repository add opam --all-switches|--set-default' to use it in all existing switches, or in newly created switches, respectively.

2025-08-15 12:00.25 ---> saved as "d7919aa9aa83e4931d2c562fbae86c0de3e0008eb24a8bc70aa4e3aa8eca70a9"

/home/opam: (run (network host)
                 (shell "opam repo add mirage-dev https://github.com/mirage/mirage-dev.git#eb114ccf0dd4eeca6b4f06c5c7361c238eeca4fd"))
[mirage-dev] Initialised
[NOTE] Repository mirage-dev has been added to the selections of switch 4.14 only.
       Run `opam repository add mirage-dev --all-switches|--set-default' to use it in all existing switches, or in newly created switches, respectively.

2025-08-15 12:00.28 ---> saved as "9f9b054a688e0de030a62ad8416f606b3395857fdff273cc13938964018e27b8"

/home/opam: (run (cache (download-cache (target /home/opam/.opam/download-cache)))
                 (network host)
                 (shell "sudo apt-get update && opam install -y \"mirage>=4\""))
Ign:1 http://deb.debian.org/debian buster InRelease
Ign:2 http://deb.debian.org/debian-security buster/updates InRelease
Ign:3 http://deb.debian.org/debian buster-updates InRelease
Err:4 http://deb.debian.org/debian buster Release
  404  Not Found [IP: 2a04:4e42:82::644 80]
Err:5 http://deb.debian.org/debian-security buster/updates Release
  404  Not Found [IP: 2a04:4e42:82::644 80]
Err:6 http://deb.debian.org/debian buster-updates Release
  404  Not Found [IP: 2a04:4e42:82::644 80]
Reading package lists...
E: The repository 'http://deb.debian.org/debian buster Release' no longer has a Release file.
E: The repository 'http://deb.debian.org/debian-security buster/updates Release' no longer has a Release file.
E: The repository 'http://deb.debian.org/debian buster-updates Release' no longer has a Release file.
"/usr/bin/env" "bash" "-c" "sudo apt-get update && opam install -y "mirage>=4"" failed with exit status 100
2025-08-15 12:00.29: Job failed: Failed: Build failed