Mounting /etc/resolv.conf failed: no such file or directory

2021-05-19 15:18.53 ---> saved as "85c1320ab1ae429fb0abc80fa220f00c2346bc50657edad3e8ddfea8ca32138e"

/: (run (cache (opam-archives (target /home/opam/.opam/download-cache)))
        (network host)
        (shell  "opam remove -y bimage-lwt.0.4.0 && opam depext -ivyt bimage-lwt.0.4.0;\
               \n        res=$?;\
               \n        test \"$res\" != 31 && exit \"$res\";\
               \n        export OPAMCLI=2.0;\
               \n        build_dir=$(opam var prefix)/.opam-switch/build;\
               \n        failed=$(ls \"$build_dir\");\
               \n        for pkg in $failed; do\
               \n          if opam show -f x-ci-accept-failures: \"$pkg\" | grep -qF \"\\\"oraclelinux-8\\\"\"; then\
               \n            echo \"A package failed and has been disabled for CI using the 'x-ci-accept-failures' field.\";\
               \n          fi;\
               \n        done;\
               \n        exit 1"))
time="2021-05-19T15:18:54Z" level=warning msg="exit status 1"
time="2021-05-19T15:18:54Z" level=error msg="container_linux.go:370: starting container process caused: process_linux.go:459: container init caused: rootfs_linux.go:59: mounting \"/etc/resolv.conf\" to rootfs at \"/var/cache/obuilder/result-tmp/0618da6351c4c1c74e51dc3b4f66ea5abe472f23150a83f94eb992da863802e6/rootfs/etc/resolv.conf\" caused: no such file or directory"
"/bin/bash" "-c"
"opam remove -y bimage-lwt.0.4.0 && opam depext -ivyt bimage-lwt.0.4.0;
        res=$?;
        test "$res" != 31 && exit "$res";
        export OPAMCLI=2.0;
        build_dir=$(opam var prefix)/.opam-switch/build;
        failed=$(ls "$build_dir");
        for pkg in $failed; do
          if opam show -f x-ci-accept-failures: "$pkg" | grep -qF "\"oraclelinux-8\""; then
            echo "A package failed and has been disabled for CI using the 'x-ci-accept-failures' field.";
          fi;
        done;
        exit 1" failed with exit status 1
2021-05-19 15:19.21: Job failed: Failed: Build failed

Full log: https://opam.ci.ocaml.org/github/ocaml/opam-repository/commit/ec85e6548c1148414fca1d6e4f407d805e995776/variant/opam-2.0,distributions,oraclelinux-8,bimage-lwt.0.4.0,tests

Start with the linked full log and the container-startup error, tracing why /etc/resolv.conf is absent from the rootfs mount target. Done means the reported obuilder build can start its container successfully without the no-such-file error.