dune dependency error with dune pkg lock #11096
Description
The #10918 introduced a bug or a regression in the way the dune pkg lock command work. I checked and the behavior wasn't present in the commit before.
Expected Behavior
When running a project with dune in the depends stanza of a dune-project file, it should build without any error. It was the previous behaviour before the mentioned PR.
Actual Behavior
The computation fails, and it prints the following stack trace:
Internal error, please report upstream including the contents of _build/log.
Description:
("can't find a valid solution for the dependencies", { name = "foo" })
Raised at Stdune__Code_error.raise in file
"otherlibs/stdune/src/code_error.ml", line 10, characters 30-62
Called from Dune_pkg__Opam_solver.reject_unreachable_packages.(fun) in file
"src/dune_pkg/opam_solver.ml", lines 830-832, characters 14-56
Called from Stdlib__Map.Make.merge in file "map.ml", line 406, characters
44-63
Called from Stdlib__Map.Make.merge in file "map.ml", line 403, characters
64-79
Called from Stdlib__Map.Make.merge in file "map.ml", line 403, characters
25-40
Called from Stdlib__Map.Make.merge in file "map.ml", line 403, characters
25-40
Called from Stdlib__Map.Make.merge in file "map.ml", line 403, characters
64-79
Called from Dune_pkg__Opam_solver.reject_unreachable_packages.(fun) in file
"src/dune_pkg/opam_solver.ml", lines 802-841, characters 6-32
Called from Dune_pkg__Opam_solver.solve_lock_dir.(fun) in file
"src/dune_pkg/opam_solver.ml", line 949, characters 10-78
Called from Fiber__Scheduler.exec in file "vendor/fiber/src/scheduler.ml",
line 76, characters 8-11
Re-raised at Stdune__Exn.raise_with_backtrace in file
"otherlibs/stdune/src/exn.ml", line 38, characters 27-56
Called from Fiber__Scheduler.exec in file "vendor/fiber/src/scheduler.ml",
line 76, characters 8-11
I must not crash. Uncertainty is the mind-killer. Exceptions are the
little-death that brings total obliteration. I will fully express my cases.
Execution will pass over me and through me. And when it has gone past, I
will unwind the stack along its path. Where the cases are handled there will
be nothing. Only I will remain.
Reproduction
You can find some logs in the binary distribution preview test: https://github.com/ocaml-dune/binary-distribution/actions/runs/11656938519/job/32453884724#step:7:49
Otherwise, to reproduce, you just need to run with an executable of dune build from main:
dune init proj foo
cd foo
dune pkg lockIf you remove the dune dependency from the (depends ...) stanza of the dune-project file, it will work without error.