kremlin transition

Error log

The package failed to build. The error log from opam follows.

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 1.2.3

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
-> retrieved opam-depext.1.2.3  (cached)
-> removed   opam-depext.1.2.3
-> installed opam-depext.1.2.3
Done.

<><> opam-depext.1.2.3 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 kremlin.transition zarith.1.14 z3.4.8.5 yojson.2.2.2 wasm.1.1.1 visitors.20210608 ulex.1.2 uchar.0.0.2 stdlib-shims.0.3.0 stdint.0.7.2 sexplib0.v0.16.0 seq.base sedlex.2.5 result.1.5 process.0.2.1 ppxlib.0.25.1 ppx_deriving_yojson.3.6.1 ppx_deriving.5.2.1 ppx_derivers.1.2.1 pprint.20230830 ocamlfind.1.9.6 ocamlbuild.0.15.0 ocaml-compiler-libs.v0.12.4 num.1.5-1 menhirSdk.20240715 menhirLib.20240715 menhirCST.20240715 menhir.20240715 karamel.1.0.0 gen.1.1 fstar.2022.01.15 fix.20230505 fileutils.0.6.4 dune.3.16.0 cppo.1.7.0 conf-python-2-7.1.2 conf-pkg-config.3 conf-gmp.4 conf-c++.1.0 camlp4.4.12+1 camlp-streams.5.0.1 batteries.3.8.0 base-bytes.base" 

Since version 2.1, opam now handles external dependencies alongside OCaml ones, and the `depext` plugin interface is provided for backwards compatibility only. Consider using your usual `opam install` command to install both OCaml and system dependencies, or `opam install <pkg> --depext-only` if you want to only install external dependencies.
# Detecting depexts using vars: arch=x86_64, os=linux, os-distribution=debian, os-family=debian
[ERROR] No solution for kremlin.transition & zarith.1.14 & z3.4.8.5 & yojson.2.2.2 & wasm.1.1.1 & visitors.20210608 & ulex.1.2 & uchar.0.0.2 & stdlib-shims.0.3.0 & stdint.0.7.2 & sexplib0.v0.16.0 & seq.base & sedlex.2.5 & result.1.5 & process.0.2.1 & ppxlib.0.25.1 & ppx_deriving_yojson.3.6.1 & ppx_deriving.5.2.1 & ppx_derivers.1.2.1 & pprint.20230830 & ocamlfind.1.9.6 & ocamlbuild.0.15.0 & ocaml-compiler-libs.v0.12.4 & num.1.5-1 & menhirSdk.20240715 & menhirLib.20240715 & menhirCST.20240715 & menhir.20240715 & karamel.1.0.0 & gen.1.1 & fstar.2022.01.15 & fix.20230505 & fileutils.0.6.4 & dune.3.16.0 & cppo.1.7.0 & conf-python-2-7.1.2 & conf-pkg-config.3 & conf-gmp.4 & conf-c++.1.0 & camlp4.4.12+1 & camlp-streams.5.0.1 & batteries.3.8.0 & base-bytes.base:   * Missing dependency:
            - conf-python-2-7
            depends on the unavailable system package 'python2.7'. 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=kremlin.transition,zarith.1.14,z3.4.8.5,yojson.2.2.2,wasm.1.1.1,visitors.20210608,ulex.1.2,uchar.0.0.2,stdlib-shims.0.3.0,stdint.0.7.2,sexplib0.v0.16.0,seq.base,sedlex.2.5,result.1.5,process.0.2.1,ppxlib.0.25.1,ppx_deriving_yojson.3.6.1,ppx_deriving.5.2.1,ppx_derivers.1.2.1,pprint.20230830,ocamlfind.1.9.6,ocamlbuild.0.15.0,ocaml-compiler-libs.v0.12.4,num.1.5-1,menhirSdk.20240715,menhirLib.20240715,menhirCST.20240715,menhir.20240715,karamel.1.0.0,gen.1.1,fstar.2022.01.15,fix.20230505,fileutils.0.6.4,dune.3.16.0,cppo.1.7.0,conf-python-2-7.1.2,conf-pkg-config.3,conf-gmp.4,conf-c++.1.0,camlp4.4.12+1,camlp-streams.5.0.1,batteries.3.8.0,base-bytes.base' --color=never returned 20