From 04ecfade8a19839595a898ef1ace9394b00fdbdc Mon Sep 17 00:00:00 2001
From: Mysaa Java <mysaa@hadoly.fr>
Date: Fri, 17 Apr 2026 16:42:11 +0200
Subject: [PATCH] ocamlPackages.elpi: Add update.sh

---
 .../ocaml-modules/elpi/default.nix            |  2 ++
 pkgs/development/ocaml-modules/elpi/update.sh | 34 +++++++++++++++++++
 2 files changed, 36 insertions(+)
 create mode 100755 pkgs/development/ocaml-modules/elpi/update.sh

diff --git a/pkgs/development/ocaml-modules/elpi/default.nix b/pkgs/development/ocaml-modules/elpi/default.nix
index 553ffabd31f8..4a2f2e50e8c0 100644
--- a/pkgs/development/ocaml-modules/elpi/default.nix
+++ b/pkgs/development/ocaml-modules/elpi/default.nix
@@ -109,6 +109,8 @@ buildDunePackage {
       ]
   );
 
+  passthru.updateScript = ./update.sh;
+
   meta = {
     description = "Embeddable λProlog Interpreter";
     license = lib.licenses.lgpl21Plus;
diff --git a/pkgs/development/ocaml-modules/elpi/update.sh b/pkgs/development/ocaml-modules/elpi/update.sh
new file mode 100755
index 000000000000..3f6cf03b9292
--- /dev/null
+++ b/pkgs/development/ocaml-modules/elpi/update.sh
@@ -0,0 +1,34 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p curl gnugrep gnused jq
+
+set -euo pipefail
+
+cd $(dirname ${BASH_SOURCE[0]})
+
+# Detect latest tag
+latestVersion=$(curl --silent ${GITHUB_TOKEN:+-u ":$GITHUB_TOKEN"} \
+    'https://api.github.com/repos/LPCIC/elpi/releases' | jq -r 'map(.tag_name).[0]' | sed 's/^v//')
+
+# Detect current tag
+currentVersion=$(sed -e "/    if lib.versionAtLeast ocaml.version \"4.13\" then/{n;q}" default.nix | tail -n 1 | sed 's/[[:space:]"]//g')
+
+if [ "$latestVersion" == "$currentVersion" ]
+then
+  echo "Already up to date"
+  exit 0
+fi
+
+# Get hash for latest tag
+versionCommit=$(curl --silent ${GITHUB_TOKEN:+-u ":$GITHUB_TOKEN"} \
+    'https://api.github.com/repos/LPCIC/elpi/tags' | \
+    jq -r "map(select(.name == \"v$latestVersion\")) | .[0] | .commit.sha")
+
+ELPI_GIT_PREFETCH=$(nix-prefetch-url --unpack https://github.com/LPCIC/elpi/archive/${versionCommit}.tar.gz)
+ELPI_GIT_HASH=$(nix --extra-experimental-features nix-command hash convert --to sri --hash-algo sha256 ${ELPI_GIT_PREFETCH})
+
+# We register the new version
+sed "/fetched = coqPackages.metaFetch {/a\\    release.\"$latestVersion\".sha256 = \"$ELPI_GIT_HASH\";" -i default.nix
+
+# We set it as default
+sed "/    if lib.versionAtLeast ocaml.version \"4.13\" then/{n;d}" -i default.nix
+sed "/    else if lib.versionAtLeast ocaml.version \"4.08\" then/i\\      \"$latestVersion\"" -i default.nix