From 809551a5fed82c75ed393e61b6c7014ad5479751 Mon Sep 17 00:00:00 2001
From: Kate <kit.ty.kate@disroot.org>
Date: Sun, 8 Aug 2021 16:25:14 +0100
Subject: [PATCH] depexts: Disable the detection of available packages on
 RHEL-based distributions

---
 master_changes.md            |  4 ++++
 src/state/opamSysInteract.ml | 28 ++++------------------------
 2 files changed, 8 insertions(+), 24 deletions(-)

diff --git a/master_changes.md b/master_changes.md
index df5e48a4aef..8d2b7ef3833 100644
--- a/master_changes.md
+++ b/master_changes.md
@@ -61,6 +61,10 @@ users)
 ## External dependencies
   * Set DEBIAN_FRONTEND=noninteractive for unsafe-yes confirmation level [#4735 @dra27 - partially fix #4731] [2.1.0~rc2 #4739]
   * Fix depext alpine tagged repositories handling [#4763 @rjbou] [2.1.0~rc2 #4758]
+  * Disable the detection of available packages on RHEL-based distributions.
+    This fixes an issue on RHEL-based distributions where yum list used to detect available
+    and installed packages would wait for user input without showing any output and/or fail
+    in some cases [#4791 @kit-ty-kate - fixes #4790]
 
 ## Format upgrade
   * Fix format upgrade when there is missing local switches in the config file [#4763 @rjbou - fix #4713] [2.1.0~rc2 #4715]
diff --git a/src/state/opamSysInteract.ml b/src/state/opamSysInteract.ml
index 9ae0aa713c4..d5e5a4bc0a5 100644
--- a/src/state/opamSysInteract.ml
+++ b/src/state/opamSysInteract.ml
@@ -286,30 +286,9 @@ let packages_status packages =
     in
     compute_sets sys_installed ~sys_available
   | Centos ->
-    (* XXX /!\ only checked on centos XXX *)
-    let lines = run_query_command "yum" ["-q"; "-C"; "list"] in
-    (* -C to retrieve from cache, no update but still quite long, 1,5 sec *)
-    (* Return a list of installed packages then available ones:
-       >Installed Packages
-       >foo.arch    version   repo
-       >Available Packages
-       >bar.arch    version   repo
-    *)
-    let sys_installed, sys_available, _ =
-      List.fold_left (fun (inst,avail,part) -> function
-          (* beware of locales!! *)
-          | "Installed Packages" -> inst, avail, `installed
-          | "Available Packages" -> inst, avail, `available
-          | l ->
-            (match part, OpamStd.String.split l '.' with
-             | `installed, pkg::_ ->
-               pkg +++ inst, avail, part
-             | `available, pkg::_ ->
-               inst, pkg +++ avail, part
-             | _ -> (* shouldn't happen *) inst, avail, part))
-        OpamSysPkg.Set.(empty, empty, `preamble) lines
-    in
-    compute_sets sys_installed ~sys_available
+    let lines = run_query_command "rpm" ["-qa"; "--qf"; "%{NAME}\\n"] in
+    let sys_installed = OpamSysPkg.Set.of_list (List.map OpamSysPkg.of_string lines) in
+    compute_sets sys_installed
   | Debian ->
     let sys_available, sys_provides, _ =
       let provides_sep = Re.(compile @@ str ", ") in
@@ -582,6 +561,7 @@ let install_packages_commands_t sys_packages =
   | Arch -> ["pacman", "-Su"::yes ["--noconfirm"] packages], None
   | Centos ->
     (* TODO: check if they all declare "rhel" as primary family *)
+    (* Kate's answer: no they don't :( (e.g. Fedora, Oraclelinux define Nothing and "fedora" respectively)  *)
     (* When opam-packages specify the epel-release package, usually it
        means that other dependencies require the EPEL repository to be
        already setup when yum-install is called. Cf. opam-depext/#70,#76. *)