Dune fails to be compiled after pinngs. Env variable works around bad version of stdune-unstable

Log.txt

➜  ~ OPAMIGNORECONSTRAINTS=stdune-unstable opam pin add [email protected]:Kakadu/dune.git\#dune-sites-test --yes                                  4.12.0+options
This will pin the following packages: dune-action-plugin, dune-bench, dune-build-info, dune-configurator, dune-glob, dune-private-libs, dune-rpc-lwt,
dune-rpc, dune-site, dune, dyn, stdune-unstable, xdg. Continue? [Y/n] y
[NOTE] Package dune-action-plugin is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.9.1).
dune-action-plugin is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.9.1)
[NOTE] Package dune-bench is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version ~dev).
dune-bench is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version ~dev)
[NOTE] Package dune-build-info is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.9.0).
dune-build-info is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.9.0)
[NOTE] Package dune-configurator is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.8.5).
dune-configurator is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.8.5)
[NOTE] Package dune-glob is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.9.1).
dune-glob is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.9.1)
[NOTE] Package dune-private-libs is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.9.1).
dune-private-libs is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.9.1)
[NOTE] Package dune-rpc-lwt is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version ~dev).
dune-rpc-lwt is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version ~dev)
[NOTE] Package dune-rpc is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version ~dev).
dune-rpc is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version ~dev)
[NOTE] Package dune-site is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.9.1).
dune-site is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.9.1)
[NOTE] Package dune is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.9.0).
dune is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version 2.9.0)
[NOTE] Package dyn is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version ~dev).
dyn is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version ~dev)
[NOTE] Package stdune-unstable is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version ~dev).
stdune-unstable is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version ~dev)
[NOTE] Package xdg is already pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version ~dev).
xdg is now pinned to git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test (version ~dev)

The following actions will be performed:
  - install stdune-unstable    ~dev*
  - install result             1.5    [required by dune-configurator, dune-rpc-lwt]
  - install dune-bench         ~dev*
  - install dune-rpc           ~dev*
  - install dune-private-libs  2.9.1*
  - install dune-configurator  2.8.5*
  - install dune-site          2.9.1*
  - install dune-glob          2.9.1*
  - install lwt                5.4.2  [required by dune-rpc-lwt]
  - install dune-action-plugin 2.9.1*
  - install dune-rpc-lwt       ~dev*
===== 11 to install =====

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
-> retrieved dune-bench.~dev  (no changes)
-> retrieved dune-action-plugin.2.9.1  (no changes)
-> retrieved dune-configurator.2.8.5  (no changes)
-> retrieved dune-glob.2.9.1  (no changes)
-> retrieved dune-rpc.~dev  (no changes)
-> retrieved dune-private-libs.2.9.1  (no changes)
-> retrieved dune-rpc-lwt.~dev  (no changes)
-> retrieved result.1.5  (cached)
-> retrieved dune-site.2.9.1  (no changes)
-> retrieved stdune-unstable.~dev  (no changes)
-> installed result.1.5
-> retrieved lwt.5.4.2  (https://opam.ocaml.org/cache)
[ERROR] The compilation of dune-bench.~dev failed at "dune build dune-bench -j 7 dune-bench.install --release".
-> installed dune-configurator.2.8.5
[ERROR] The compilation of stdune-unstable.~dev failed at "dune build -p stdune-unstable -j 7 @install".
-> installed lwt.5.4.2

#=== ERROR while compiling stdune-unstable.~dev ===============================#
# context     2.1.0 | linux/x86_64 | ocaml-options-only-flambda.1 | pinned(git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test#ac872fff)
# path        /media/mand/.opam/4.12.0+options/.opam-switch/build/stdune-unstable.~dev
# command     /media/mand/.opam/opam-init/hooks/sandbox.sh build dune build -p stdune-unstable -j 7 @install
# exit-code   1
# env-file    /media/mand/.opam/log/stdune-unstable-25738-520af6.env
# output-file /media/mand/.opam/log/stdune-unstable-25738-520af6.out
### output ###
# Error: The files /media/mand/.opam/4.12.0+options/lib/dyn/dyn.cmi
# [...]
# (cd _build/default && /media/mand/.opam/4.12.0+options/bin/ocamlc.opt -w -40 -g -bin-annot -I otherlibs/stdune-unstable/.stdune.objs/byte -I /media/mand/.opam/4.12.0+options/lib/csexp -I /media/mand/.opam/4.12.0+options/lib/dyn -I /media/mand/.opam/4.12.0+options/lib/pp -I otherlibs/stdune-unstable/dune_filesystem_stubs/.dune_filesystem_stubs.objs/byte -no-alias-deps -open Stdune__ -o otherli[...]
# File "otherlibs/stdune-unstable/exn_with_backtrace.mli", line 1:
# Error: The files otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Result.cmi
#        and /media/mand/.opam/4.12.0+options/lib/pp/pp.cmi
#        make inconsistent assumptions over interface Pp
#       ocamlc otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Loc.{cmi,cmti} (exit 2)
# (cd _build/default && /media/mand/.opam/4.12.0+options/bin/ocamlc.opt -w -40 -g -bin-annot -I otherlibs/stdune-unstable/.stdune.objs/byte -I /media/mand/.opam/4.12.0+options/lib/csexp -I /media/mand/.opam/4.12.0+options/lib/dyn -I /media/mand/.opam/4.12.0+options/lib/pp -I otherlibs/stdune-unstable/dune_filesystem_stubs/.dune_filesystem_stubs.objs/byte -no-alias-deps -open Stdune__ -o otherli[...]
# File "otherlibs/stdune-unstable/loc.mli", line 1:
# Error: The files otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Loc0.cmi
#        and /media/mand/.opam/4.12.0+options/lib/pp/pp.cmi
#        make inconsistent assumptions over interface Pp


#=== ERROR while compiling dune-bench.~dev ====================================#
# context     2.1.0 | linux/x86_64 | ocaml-options-only-flambda.1 | pinned(git+ssh://[email protected]/Kakadu/dune.git#dune-sites-test#ac872fff)
# path        /media/mand/.opam/4.12.0+options/.opam-switch/build/dune-bench.~dev
# command     /media/mand/.opam/opam-init/hooks/sandbox.sh build dune build dune-bench -j 7 dune-bench.install --release
# exit-code   1
# env-file    /media/mand/.opam/log/dune-bench-25738-c54dbc.env
# output-file /media/mand/.opam/log/dune-bench-25738-c54dbc.out
### output ###
# Error: Don't know how to build dune-bench



<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
+- The following actions failed
| - build dune-bench      ~dev
| - build stdune-unstable ~dev
+- 
+- The following changes have been performed (the rest was aborted)
| - install dune-configurator 2.8.5
| - install lwt               5.4.2
| - install result            1.5
+- 
[NOTE] Pinning command successful, but your installed packages may be out of sync.

The former state can be restored with:
    /usr/local/bin/opam switch import "/media/mand/.opam/4.12.0+options/.opam-switch/backup/state-20211004145711.export"
➜  ~                                                                                                                                           4.12.0+options

stdune-unstable-25738-520af6.out

➜  ~ cat /media/mand/.opam/log/stdune-unstable-25738-520af6.out                                                                                4.12.0+options
      ocamlc otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Exn.{cmi,cmti} (exit 2)
(cd _build/default && /media/mand/.opam/4.12.0+options/bin/ocamlc.opt -w -40 -g -bin-annot -I otherlibs/stdune-unstable/.stdune.objs/byte -I /media/mand/.opam/4.12.0+options/lib/csexp -I /media/mand/.opam/4.12.0+options/lib/dyn -I /media/mand/.opam/4.12.0+options/lib/pp -I otherlibs/stdune-unstable/dune_filesystem_stubs/.dune_filesystem_stubs.objs/byte -no-alias-deps -open Stdune__ -o otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Exn.cmi -c -intf otherlibs/stdune-unstable/exn.mli)
File "otherlibs/stdune-unstable/exn.mli", line 1:
Error: The files /media/mand/.opam/4.12.0+options/lib/pp/pp.cmi
       and /media/mand/.opam/4.12.0+options/lib/dyn/dyn.cmi
       make inconsistent assumptions over interface Pp
      ocamlc otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Sexp.{cmi,cmti} (exit 2)
(cd _build/default && /media/mand/.opam/4.12.0+options/bin/ocamlc.opt -w -40 -g -bin-annot -I otherlibs/stdune-unstable/.stdune.objs/byte -I /media/mand/.opam/4.12.0+options/lib/csexp -I /media/mand/.opam/4.12.0+options/lib/dyn -I /media/mand/.opam/4.12.0+options/lib/pp -I otherlibs/stdune-unstable/dune_filesystem_stubs/.dune_filesystem_stubs.objs/byte -no-alias-deps -open Stdune__ -o otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Sexp.cmi -c -intf otherlibs/stdune-unstable/sexp.mli)
File "otherlibs/stdune-unstable/sexp.mli", line 1:
Error: The files /media/mand/.opam/4.12.0+options/lib/pp/pp.cmi
       and /media/mand/.opam/4.12.0+options/lib/dyn/dyn.cmi
       make inconsistent assumptions over interface Pp
      ocamlc otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Ansi_color.{cmi,cmti} (exit 2)
(cd _build/default && /media/mand/.opam/4.12.0+options/bin/ocamlc.opt -w -40 -g -bin-annot -I otherlibs/stdune-unstable/.stdune.objs/byte -I /media/mand/.opam/4.12.0+options/lib/csexp -I /media/mand/.opam/4.12.0+options/lib/dyn -I /media/mand/.opam/4.12.0+options/lib/pp -I otherlibs/stdune-unstable/dune_filesystem_stubs/.dune_filesystem_stubs.objs/byte -no-alias-deps -open Stdune__ -o otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Ansi_color.cmi -c -intf otherlibs/stdune-unstable/ansi_color.mli)
File "otherlibs/stdune-unstable/ansi_color.mli", line 1:
Error: The files /media/mand/.opam/4.12.0+options/lib/dyn/dyn.cmi
       and /media/mand/.opam/4.12.0+options/lib/pp/pp.cmi
       make inconsistent assumptions over interface Pp
      ocamlc otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Exn_with_backtrace.{cmi,cmti} (exit 2)
(cd _build/default && /media/mand/.opam/4.12.0+options/bin/ocamlc.opt -w -40 -g -bin-annot -I otherlibs/stdune-unstable/.stdune.objs/byte -I /media/mand/.opam/4.12.0+options/lib/csexp -I /media/mand/.opam/4.12.0+options/lib/dyn -I /media/mand/.opam/4.12.0+options/lib/pp -I otherlibs/stdune-unstable/dune_filesystem_stubs/.dune_filesystem_stubs.objs/byte -no-alias-deps -open Stdune__ -o otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Exn_with_backtrace.cmi -c -intf otherlibs/stdune-unstable/exn_with_backtrace.mli)
File "otherlibs/stdune-unstable/exn_with_backtrace.mli", line 1:
Error: The files otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Result.cmi
       and /media/mand/.opam/4.12.0+options/lib/pp/pp.cmi
       make inconsistent assumptions over interface Pp
      ocamlc otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Loc.{cmi,cmti} (exit 2)
(cd _build/default && /media/mand/.opam/4.12.0+options/bin/ocamlc.opt -w -40 -g -bin-annot -I otherlibs/stdune-unstable/.stdune.objs/byte -I /media/mand/.opam/4.12.0+options/lib/csexp -I /media/mand/.opam/4.12.0+options/lib/dyn -I /media/mand/.opam/4.12.0+options/lib/pp -I otherlibs/stdune-unstable/dune_filesystem_stubs/.dune_filesystem_stubs.objs/byte -no-alias-deps -open Stdune__ -o otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Loc.cmi -c -intf otherlibs/stdune-unstable/loc.mli)
File "otherlibs/stdune-unstable/loc.mli", line 1:
Error: The files otherlibs/stdune-unstable/.stdune.objs/byte/stdune__Loc0.cmi
       and /media/mand/.opam/4.12.0+options/lib/pp/pp.cmi
       make inconsistent assumptions over interface Pp