Merge pull request #269 from NathanReb/deal-with-avoid-version

Prevent unecessary selection of beta versions

CHANGES.md

@@ -30,6 +30,8 @@
 
 - Fix a bug where a package which had a single version that built with dune and got selected by the solver
   would be reported has having no version building with dune. (#245, @Leonidas-from-XIV)
+- Fix the solver so it does not select beta versions of the compiler unless
+  forced to by version constraints or `--ocaml-version`. (#269, @NathanReb)
 
 ### Removed
 

lib/opam.ml

@@ -48,6 +48,10 @@ let version_is_at_least locked_version =
   let version_formula = OpamFormula.Atom version_constraint in
   OpamFormula.check_version_formula version_formula
 
+let avoid_version opam =
+  let flags = OpamFile.OPAM.flags opam in
+  List.mem ~set:flags OpamTypes.Pkgflag_AvoidVersion
+
 let pull_tree ~url ~hashes ~dir global_state =
   let dir_str = Fpath.to_string dir in
   let cache_dir =

lib/opam.mli

@@ -149,6 +149,11 @@ module Value : sig
   end
 end
 
+val avoid_version : OpamFile.OPAM.t -> bool
+(** Returns whether this version should be avoided by telling whether it has
+    the avoid-version flag.
+    This flag is set for the compiler beta releases for instance. *)
+
 val depends_on_dune : allow_jbuilder:bool -> OpamTypes.filtered_formula -> bool
 (** Returns whether the given depends field formula contains a dependency to dune or jbuilder *)
 

lib/opam_solve.ml

@@ -152,6 +152,15 @@ module Opam_monorepo_context (Base_context : BASE_CONTEXT) :
                    in
                    (version, Ok opam_file))
 
+  let demote_candidates_to_avoid versions =
+    let avoid_versions, regular_versions =
+      List.partition versions ~f:(fun (_version, opam_res) ->
+          match opam_res with
+          | Ok opam -> Opam.avoid_version opam
+          | Error _ -> false)
+    in
+    regular_versions @ avoid_versions
+
   let candidates
       {
         base_context;
@@ -170,6 +179,7 @@ module Opam_monorepo_context (Base_context : BASE_CONTEXT) :
         Base_context.candidates base_context name
         |> filter_candidates ~allow_jbuilder ~require_dune ~name
         |> remove_opam_provided ~opam_provided
+        |> demote_candidates_to_avoid
 
   let user_restrictions { base_context; _ } name =
     Base_context.user_restrictions base_context name

test/bin/compiler-beta.t/repo-with-beta-ocaml/packages/ocaml-base-compiler/ocaml-base-compiler.4.14.0~beta1/opam

@@ -0,0 +1,45 @@
+opam-version: "2.0"
+synopsis: "First beta release of OCaml 4.14.0"
+maintainer: "[email protected]"
+license: "LGPL-2.1-or-later WITH OCaml-LGPL-linking-exception"
+authors: "Xavier Leroy and many contributors"
+homepage: "https://ocaml.org"
+bug-reports: "https://github.com/ocaml/opam-repository/issues"
+dev-repo: "git+https://github.com/ocaml/ocaml#4.14"
+depends: [
+  "ocaml" {= "4.14.0" & post}
+  "base-unix" {post}
+  "base-bigarray" {post}
+  "base-threads" {post}
+  "ocaml-options-vanilla" {post}
+  "ocaml-beta" {opam-version < "2.1.0"}
+]
+conflict-class: "ocaml-core-compiler"
+flags: [ compiler avoid-version ]
+setenv: CAML_LD_LIBRARY_PATH = "%{lib}%/stublibs"
+build: [
+  [
+    "./configure"
+    "--prefix=%{prefix}%"
+    "--docdir=%{doc}%/ocaml"
+    "-C"
+    "CC=cc" {os = "openbsd" | os = "macos"}
+    "ASPP=cc -c" {os = "openbsd" | os = "macos"}
+  ]
+  [make "-j%{jobs}%"]
+]
+install: [make "install"]
+url {
+  src: "https://github.com/ocaml/ocaml/archive/4.14.0-beta1.tar.gz"
+  checksum: "sha256=1b02000867fd20af59c2afa1eda411d064f02cf96227f7f3e07fbeb5492abe95"
+}
+extra-files: ["ocaml-base-compiler.install" "md5=3e969b841df1f51ca448e6e6295cb451"]
+post-messages: [
+  "A failure in the middle of the build may be caused by build parallelism
+   (enabled by default).
+   Please file a bug report at https://github.com/ocaml/opam-repository/issues"
+  {failure & jobs > 1}
+  "You can try installing again including --jobs=1
+   to force a sequential build instead."
+  {failure & jobs > 1 & opam-version >= "2.0.5"}
+]

test/bin/compiler-beta.t/repo-with-beta-ocaml/packages/ocaml/ocaml.4.14.0/opam

@@ -0,0 +1,31 @@
+opam-version: "2.0"
+license: "LGPL-2.1-or-later WITH OCaml-LGPL-linking-exception"
+synopsis: "The OCaml compiler (virtual package)"
+description: """
+This package requires a matching implementation of OCaml,
+and polls it to initialise specific variables like `ocaml:native-dynlink`"""
+maintainer: "[email protected]"
+depends: [
+  "ocaml-config" {>= "2"}
+  "ocaml-base-compiler" {>= "4.14.0~" & < "4.14.1~"} |
+  "ocaml-variants" {>= "4.14.0~" & < "4.14.1~"} |
+  "ocaml-system" {>= "4.14.0" & < "4.14.1~"}
+]
+setenv: [
+  [CAML_LD_LIBRARY_PATH = "%{_:stubsdir}%"]
+  [CAML_LD_LIBRARY_PATH += "%{lib}%/stublibs"]
+  [OCAML_TOPLEVEL_PATH = "%{toplevel}%"]
+]
+build: ["ocaml" "%{ocaml-config:share}%/gen_ocaml_config.ml" _:version _:name]
+build-env: CAML_LD_LIBRARY_PATH = ""
+homepage: "https://ocaml.org"
+bug-reports: "https://github.com/ocaml/opam-repository/issues"
+authors: [
+  "Xavier Leroy"
+  "Damien Doligez"
+  "Alain Frisch"
+  "Jacques Garrigue"
+  "Didier Rémy"
+  "Jérôme Vouillon"
+]
+flags: conf

test/bin/compiler-beta.t/repo-with-beta-ocaml/repo

@@ -0,0 +1 @@
+opam-version: "2.0"

test/bin/compiler-beta.t/run.t

@@ -0,0 +1,43 @@
+We have a simple project that only depends on OCaml
+
+  $ opam show --no-lint -fdepends ./test.opam
+  "ocaml" "dune"
+
+We use the minimal repository which includes OCaml 4.13.1
+
+  $ gen-minimal-repo
+
+We also use an extra repository which contains the packages of the ongoing beta
+release of OCaml 4.14.0 i.e. ocaml.4.14.0 and ocaml-base-compiler.4.14.0~beta1.
+Those are the actual opam files extracted from upstream opam-repository. The
+relevant part to this feature is that the ocaml-base-compiler package has the
+avoid-version flag:
+
+  $ opam show --no-lint -fflags repo-with-beta-ocaml/packages/ocaml-base-compiler/ocaml-base-compiler.4.14.0~beta1/opam
+  compiler avoid-version
+
+Our package does not define an upper bound on ocaml but the beta should not be
+selected by default if there exists another solution, therefore here the solver
+should pick 4.13.1:
+
+  $ opam-monorepo lock test > /dev/null
+  $ opam show --no-lint -fdepends ./test.opam.locked | grep ocaml
+  "ocaml" {= "4.13.1"}
+  "ocaml-base-compiler" {= "4.13.1"}
+  "ocaml-config" {= "2"}
+  "ocaml-options-vanilla" {= "1"}
+
+Now if we require ocaml >= 4.14, as the following package does:
+
+  $ opam show --no-lint -fdepends ./test-requires-beta.opam
+  "ocaml" {>= "4.14"} "dune"
+
+The solver should be able to select the beta compiler since it is the only
+satisfying version available:
+
+  $ opam-monorepo lock test-requires-beta > /dev/null
+  $ opam show --no-lint -fdepends ./test-requires-beta.opam.locked | grep ocaml
+  "ocaml" {= "4.14.0"}
+  "ocaml-base-compiler" {= "4.14.0~beta1"}
+  "ocaml-config" {= "2"}
+  "ocaml-options-vanilla" {= "1"}

test/bin/compiler-beta.t/test-requires-beta.opam

@@ -0,0 +1,9 @@
+opam-version: "2.0"
+depends: [
+  "ocaml" {>= "4.14"}
+  "dune"
+]
+x-opam-monorepo-opam-repositories: [
+  "file://$OPAM_MONOREPO_CWD/minimal-repo"
+  "file://$OPAM_MONOREPO_CWD/repo-with-beta-ocaml"
+]

test/bin/compiler-beta.t/test.opam

@@ -0,0 +1,9 @@
+opam-version: "2.0"
+depends: [
+  "ocaml"
+  "dune"
+]
+x-opam-monorepo-opam-repositories: [
+  "file://$OPAM_MONOREPO_CWD/minimal-repo"
+  "file://$OPAM_MONOREPO_CWD/repo-with-beta-ocaml"
+]