From 7a06496960f2fa7656b1469b0fa7381cc460aed4 Mon Sep 17 00:00:00 2001
From: Kate <kit-ty-kate@outlook.com>
Date: Wed, 20 Nov 2024 16:16:11 +0000
Subject: [PATCH] Remove ocaml-system from the list of default compilers used
 during opam init

Co-authored-by: Raja Boujbel <raja.boujbel@ocamlpro.com>
---
 master_changes.md              |  2 ++
 src/client/opamInitDefaults.ml |  8 ++-----
 tests/reftests/init.test       | 44 ++++++++++++++++++----------------
 3 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/master_changes.md b/master_changes.md
index 20de91332f9..cf2b8c056f7 100644
--- a/master_changes.md
+++ b/master_changes.md
@@ -20,6 +20,7 @@ users)
 
 ## Init
   * [BUG] Fix the detection of `ZDOTDIR` when using `zsh` [#6299 @acasta-yhliu - fix #6281]
+  * Remove `ocaml-system` from the list of default compilers [#6307 @kit-ty-kate - fix #3509]
 
 ## Config report
 
@@ -178,6 +179,7 @@ users)
   * Add a test showing the behaviour of `opam upgrade` with packages flagged with `avoid-version`/`deprecated` [#6273 @kit-ty-kate]
   * Add a test showing the behaviour when a pin depend is unpinned [#6380 @rjbou]
   * Add a test to ensure `opam upgrade <pkg>` will not upgrade unrelated things [#6373 @kit-ty-kate]
+  * Add a test in init to show ocaml system compiler selection behaviour [#6307 @kit-ty-kate @rjbou]
 
 ### Engine
 
diff --git a/src/client/opamInitDefaults.ml b/src/client/opamInitDefaults.ml
index f8639576412..c077b787766 100644
--- a/src/client/opamInitDefaults.ml
+++ b/src/client/opamInitDefaults.ml
@@ -19,12 +19,8 @@ let repository_url = {
 }
 
 let default_compiler =
-  OpamFormula.ors [
-    OpamFormula.Atom (OpamPackage.Name.of_string "ocaml-system",
-                      OpamFormula.Empty);
-    OpamFormula.Atom (OpamPackage.Name.of_string "ocaml-base-compiler",
-                      OpamFormula.Empty);
-  ]
+  OpamFormula.Atom (OpamPackage.Name.of_string "ocaml-base-compiler",
+                    OpamFormula.Empty)
 
 let default_invariant =
   OpamFormula.Atom
diff --git a/tests/reftests/init.test b/tests/reftests/init.test
index 8fcb46acdf4..dfac9899fbf 100644
--- a/tests/reftests/init.test
+++ b/tests/reftests/init.test
@@ -110,7 +110,7 @@ Switch invariant: ["ocaml" {>= "4.05.0"}]
 Done.
 ### opam switch invariant
 ["ocaml" {>= "4.05.0"}]
-### :I:3: System compiler = 4.07.0, should be selected default
+### :I:3: Base compiler should be selected default
 ### rm -rf ${OPAMROOT}
 ### <opamrc>
 eval-variables: [ sys-ocaml-version ["echo" "4.07.0"] "new system compiler" ]
@@ -120,36 +120,38 @@ Configuring from ${BASEDIR}/opamrc and then from built-in defaults.
 <><> Fetching repository information ><><><><><><><><><><><><><><><><><><><><><>
 [default] Initialised
 
-<><> Creating initial switch 'default' (invariant ["ocaml" {>= "4.05.0"}] - initially with ocaml-system)
+<><> Creating initial switch 'default' (invariant ["ocaml" {>= "4.05.0"}] - initially with ocaml-base-compiler)
 
 <><> Installing new switch packages <><><><><><><><><><><><><><><><><><><><><><>
 Switch invariant: ["ocaml" {>= "4.05.0"}]
 
 <><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
--> installed ocaml-system.4.07.0
--> installed ocaml.4.07.0
+-> installed ocaml-base-compiler.4.10.0
+-> installed ocaml.4.10.0
 Done.
 ### opam switch invariant
 ["ocaml" {>= "4.05.0"}]
-### opam upgrade
-Everything as up-to-date as possible (run with --verbose to show unavailable upgrades).
-However, you may "opam upgrade" these packages explicitly at these versions (e.g. "opam upgrade ocaml.4.10.0"), which will ask permission to downgrade or uninstall the conflicting packages.
-Nothing to do.
-### opam upgrade ocaml
-The following actions will be performed:
-=== remove 1 package
-  - remove  ocaml-system        4.07.0           [conflicts with ocaml-base-compiler]
-=== upgrade 1 package
-  - upgrade ocaml               4.07.0 to 4.10.0
-=== install 1 package
-  - install ocaml-base-compiler 4.10.0           [required by ocaml]
+### :I:4: ocaml-system explicit selection
+### rm -rf $OPAMROOT
+### <opamrc>
+eval-variables: [ sys-ocaml-version ["echo" "4.07.0"] "new system compiler" ]
+### opam init --no-setup --bypass-checks default REPO/ --config opamrc -c ocaml-system | grep -v Cygwin
+Configuring from ${BASEDIR}/opamrc and then from built-in defaults.
+
+<><> Fetching repository information ><><><><><><><><><><><><><><><><><><><><><>
+[default] Initialised
+
+<><> Creating initial switch 'ocaml-system' (invariant ["ocaml-system"]) ><><><>
+
+<><> Installing new switch packages <><><><><><><><><><><><><><><><><><><><><><>
+Switch invariant: ["ocaml-system"]
 
 <><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
--> removed   ocaml.4.07.0
--> removed   ocaml-system.4.07.0
--> installed ocaml-base-compiler.4.10.0
--> installed ocaml.4.10.0
+-> installed ocaml-system.4.07.0
+-> installed ocaml.4.07.0
 Done.
+### opam switch invariant
+["ocaml-system"]
 ### :II: Init with config file :
 ### :II:a: default setup ::
 ### rm -rf $OPAMROOT
@@ -159,7 +161,7 @@ No configuration file found, using built-in defaults.
 <><> Fetching repository information ><><><><><><><><><><><><><><><><><><><><><>
 [default] Initialised
 ### opam-cat $OPAMROOT/config | 'opam-root-version: "${OPAMROOTVERSION}"' -> 'opam-root-version: current' | grep -v sys-pkg-manager-cmd | grep -v global-variables | grep -v eval-variables:
-default-compiler: ["ocaml-system" "ocaml-base-compiler"]
+default-compiler: ["ocaml-base-compiler"]
 default-invariant: ["ocaml" {>= "4.05.0"}]
 depext: true
 depext-cannot-install: false