From 8d48810ab0571a3b11ca229200233adfc212f665 Mon Sep 17 00:00:00 2001
From: Thomas Gerbet <thomas@gerbet.me>
Date: Sat, 25 Jul 2026 13:27:09 +0200
Subject: [PATCH] nix-cl: avoid empty path segments in prefixed env variables

(cherry picked from commit 6bf6d4c64fa3673ec19b33aef7481938d05a5cbb)
---
 pkgs/development/lisp-modules/nix-cl.nix | 42 +++++++++++++++++-------
 1 file changed, 30 insertions(+), 12 deletions(-)

diff --git a/pkgs/development/lisp-modules/nix-cl.nix b/pkgs/development/lisp-modules/nix-cl.nix
index 8441f9e90f56..be418d13f9a9 100644
--- a/pkgs/development/lisp-modules/nix-cl.nix
+++ b/pkgs/development/lisp-modules/nix-cl.nix
@@ -365,18 +365,36 @@ let
         nativeBuildInputs = [ pkgs.makeBinaryWrapper ];
         installPhase = ''
           mkdir -pv $out/bin
-          makeWrapper \
-            ${o.pkg}/bin/${o.program} \
-            $out/bin/${o.program} \
-            --add-flags "${toString o.flags}" \
-            --set ASDF "${o.asdfFasl}/asdf.${o.faslExt}" \
-            --prefix CL_SOURCE_REGISTRY : "$CL_SOURCE_REGISTRY''${CL_SOURCE_REGISTRY:+:}" \
-            --prefix ASDF_OUTPUT_TRANSLATIONS : "$(echo $CL_SOURCE_REGISTRY | sed s,//:,::,g):" \
-            --prefix LD_LIBRARY_PATH : "$LD_LIBRARY_PATH" \
-            --prefix DYLD_LIBRARY_PATH : "$DYLD_LIBRARY_PATH" \
-            --prefix CLASSPATH : "$CLASSPATH" \
-            --prefix GI_TYPELIB_PATH : "$GI_TYPELIB_PATH" \
-            --prefix PATH : "${makeBinPath (o.propagatedBuildInputs or [ ])}"
+
+          wrapperArgs=(
+            "${o.pkg}/bin/${o.program}"
+            "$out/bin/${o.program}"
+            --add-flags "${toString o.flags}"
+            --set ASDF "${o.asdfFasl}/asdf.${o.faslExt}"
+          )
+          if [ -n "$CL_SOURCE_REGISTRY" ]; then
+            wrapperArgs+=(
+              --prefix CL_SOURCE_REGISTRY : "$CL_SOURCE_REGISTRY:"
+              --prefix ASDF_OUTPUT_TRANSLATIONS : "$(echo $CL_SOURCE_REGISTRY | sed s,//:,::,g):"
+            )
+          fi
+          if [ -n "$LD_LIBRARY_PATH" ]; then
+            wrapperArgs+=(--prefix LD_LIBRARY_PATH : "$LD_LIBRARY_PATH")
+          fi
+          if [ -n "$DYLD_LIBRARY_PATH" ]; then
+            wrapperArgs+=(--prefix DYLD_LIBRARY_PATH : "$DYLD_LIBRARY_PATH")
+          fi
+          if [ -n "$CLASSPATH" ]; then
+            wrapperArgs+=(--prefix CLASSPATH : "$CLASSPATH")
+          fi
+          if [ -n "$GI_TYPELIB_PATH" ]; then
+            wrapperArgs+=(--prefix GI_TYPELIB_PATH : "$GI_TYPELIB_PATH")
+          fi
+          ${lib.optionalString ((o.propagatedBuildInputs or [ ]) != [ ]) ''
+            wrapperArgs+=(--prefix PATH : "${makeBinPath (o.propagatedBuildInputs or [ ])}")
+          ''}
+
+          makeWrapper "''${wrapperArgs[@]}"
         '';
       });