--- /dev/null
+#!/bin/sh -e
+# Helper to bypass AC_ERLANG_CHECK_LIB
+#
+# Ejabberd releases do not download specific versions of its erlang
+# dependencies. Instead, it clones the master branch of a git
+# repository and asks erl to provide the library version. However,
+# the target erl program cannot be called from the host. So, this
+# script aims at finding the library version installed on the target,
+# without calling erlang.
+
+usage() {
+ cat <<EOF
+Usage:
+ $0 library
+Look for Erlang's library in TARGET_DIR/usr/lib/erlang/lib.
+
+If the library is found, it returns the path to the latest version,
+relative to TARGET_DIR. Otherwise, it returns "not found".
+
+If there are several versions, it returns an error because it does not
+know which one Erlang uses.
+
+EOF
+}
+
+die () {
+ echo "$@" >&2
+ exit 1
+}
+
+if [ $# -ne 1 ]; then
+ usage
+ exit 0
+else
+ library="$1"
+fi
+
+target_dir="${TARGET_DIR:-output/target}"
+
+[ -d "$target_dir" ] || die "TARGET_DIR is not a directory. Please \
+specify the TARGET_DIR environment variable."
+
+case "$(ls -1d -- "$target_dir/usr/lib/erlang/lib/$library-"* | wc -l)" in
+ 0)
+ echo "not found"
+ ;;
+ 1)
+ echo "$target_dir/usr/lib/erlang/lib/$library-"* \
+ | sed -e "s,^$target_dir,,"
+ ;;
+ *)
+ die "Several versions of $library have been found. Please \
+ remove the unused ones."
+ ;;
+esac