One level down to copy.

install-lua-rock.sh, which is packaged as well.

install-lua-rock.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+set -ex
+
+# 1. %{lua_version}
+# 2. %{buildroot}%{_prefix}
+# 3. %{buildroot}%{luarocks_treedir}/%{mod_name}
+
+SOURCE_DIR="$3"
+luarocks --lua-version="$1" --tree="$2" install --deps-mode=none --no-manifest "${*:$#}"
+
+if  [ -d "${SOURCE_DIR}" ] && [ "$(find "${SOURCE_DIR}" -type f | wc -l)" -gt 0 ]
+then
+  mkdir -p __rocktree
+  mv -v "${SOURCE_DIR}"/*/* __rocktree
+fi

lua-macros.changes

@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Mon Oct 20 21:30:36 UTC 2025 - Matej Cepl <mcepl@cepl.eu>
+
+- Rewrite %luarocks_install to use a shell script
+  install-lua-rock.sh, which is packaged as well.
+
 -------------------------------------------------------------------
 Tue Oct 14 23:16:09 UTC 2025 - Matej Cepl <mcepl@cepl.eu>
 

lua-macros.spec

@@ -27,6 +27,7 @@ License:        MIT
 Group:          Development/Languages/Other
 URL:            https://www.lua.org
 Source0:        macros.lua
+Source1:        install-lua-rock.sh
 %if 0%{?suse_version} > 1600
 Requires:       lua-interpreter
 %elif 0%{?suse_version} >= 1500
@@ -46,9 +47,11 @@ cp -p %{SOURCE0} .
 :
 
 %install
-install -Dm644 macros.lua %{buildroot}%{_rpmmacrodir}/macros.lua
+install -Dm644 %{SOURCE0} %{buildroot}%{_rpmmacrodir}/macros.lua
+install -Dm755 %{SOURCE1} %{buildroot}%{_rpmconfigdir}/install-lua-rock.sh
 
 %files
 %{_rpmmacrodir}/macros.lua
+%{_rpmconfigdir}/install-lua-rock.sh
 
 %changelog

macros.lua

@@ -97,7 +97,4 @@ luarocks --lua-version "%{lua_version}" make --deps-mode none --pack-binary-rock
 %luarocks_treedir %{_prefix}/lib/luarocks/rocks-%{lua_version}
 
 %luarocks_install \
-  /bin/sh -c 'luarocks --lua-version="%{lua_version}" --tree="%{buildroot}%{_prefix}" install --deps-mode=none --no-manifest "$@" && \
-  source_dir="%{buildroot}%{luarocks_treedir}/%{mod_name}/%{rock_version}" && \
-  [ -d "${source_dir}" ] && [ "$(ls -A "${source_dir}" | wc -l)" -gt 0 ] && \
-  mv -v "${source_dir}" __rocktree' --
+  %{_rpmconfigdir}/install-lua-rock.sh "%{lua_version}" "%{buildroot}%{_prefix}" "%{buildroot}%{luarocks_treedir}/%{mod_name}"