rc: fix build with "editline" library (#543003)

pkgs/by-name/rc/rc/package.nix

@@ -4,15 +4,17 @@
   fetchFromGitHub,
   fetchpatch2,
   pkgsStatic,
+  rc,
   byacc,
   ed,
   ncurses,
   readline,
+  editline,
   installShellFiles,
   historySupport ? true,
   readlineSupport ? true,
-  lineEditingLibrary ?
-    if (stdenv.hostPlatform.isDarwin || stdenv.hostPlatform.isStatic) then "null" else "readline",
+  editlineSupport ? false,
+  lineEditingLibrary ? if stdenv.hostPlatform.isDarwin then "null" else "readline",
 }:
 
 assert lib.elem lineEditingLibrary [
@@ -25,10 +27,10 @@ assert lib.elem lineEditingLibrary [
 assert
   !(lib.elem lineEditingLibrary [
     "edit"
-    "editline"
     "vrl"
   ]); # broken
 assert (lineEditingLibrary == "readline") -> readlineSupport;
+assert (lineEditingLibrary == "editline") -> editlineSupport;
 stdenv.mkDerivation (finalAttrs: {
   pname = "rc";
   version = "unstable-2025-10-01";
@@ -61,9 +63,8 @@ stdenv.mkDerivation (finalAttrs: {
   buildInputs = [
     ncurses
   ]
-  ++ lib.optionals readlineSupport [
-    readline
-  ];
+  ++ lib.optional readlineSupport readline
+  ++ lib.optional editlineSupport editline;
 
   strictDeps = true;
 
@@ -73,7 +74,9 @@ stdenv.mkDerivation (finalAttrs: {
     "MANPREFIX=${placeholder "man"}/share/man"
     "CPPFLAGS=\"-DSIGCLD=SIGCHLD\""
     "EDIT=${lineEditingLibrary}"
-  ];
+  ]
+  # Required to fix static build, harmless for dynamic builds.
+  ++ lib.optional (lineEditingLibrary == "readline") "LDLIBS=-lncurses";
 
   buildFlags = [
     "all"
@@ -88,7 +91,21 @@ stdenv.mkDerivation (finalAttrs: {
 
   passthru = {
     shellPath = "/bin/rc";
-    tests.static = pkgsStatic.rc;
+    tests = {
+      static = pkgsStatic.rc;
+      readline = lib.optionalDrvAttr (!stdenv.hostPlatform.isDarwin) (
+        rc.override {
+          readlineSupport = true;
+          lineEditingLibrary = "readline";
+        }
+      );
+      editline = lib.optionalDrvAttr (!stdenv.hostPlatform.isDarwin) (
+        rc.override {
+          editlineSupport = true;
+          lineEditingLibrary = "editline";
+        }
+      );
+    };
   };
 
   meta = {