diff --git a/pkgs/applications/editors/emacs/elisp-packages/elpa-devel-packages.nix b/pkgs/applications/editors/emacs/elisp-packages/elpa-devel-packages.nix
index 5744eaa4e5a1..0db019dddb5c 100644
--- a/pkgs/applications/editors/emacs/elisp-packages/elpa-devel-packages.nix
+++ b/pkgs/applications/editors/emacs/elisp-packages/elpa-devel-packages.nix
@@ -26,7 +26,7 @@ formats commits for you.
 
 self: let
 
-  inherit (import ./lib-override-helper.nix pkgs)
+  inherit (import ./lib-override-helper.nix pkgs lib)
     markBroken
     ;
 
diff --git a/pkgs/applications/editors/emacs/elisp-packages/elpa-packages.nix b/pkgs/applications/editors/emacs/elisp-packages/elpa-packages.nix
index d20a2249703b..64c05ba3154e 100644
--- a/pkgs/applications/editors/emacs/elisp-packages/elpa-packages.nix
+++ b/pkgs/applications/editors/emacs/elisp-packages/elpa-packages.nix
@@ -26,7 +26,7 @@ formats commits for you.
 
 self: let
 
-  inherit (import ./lib-override-helper.nix pkgs)
+  inherit (import ./lib-override-helper.nix pkgs lib)
     markBroken
     ;
 
diff --git a/pkgs/applications/editors/emacs/elisp-packages/lib-override-helper.nix b/pkgs/applications/editors/emacs/elisp-packages/lib-override-helper.nix
index fb1f412299f7..6eddcc2f9f75 100644
--- a/pkgs/applications/editors/emacs/elisp-packages/lib-override-helper.nix
+++ b/pkgs/applications/editors/emacs/elisp-packages/lib-override-helper.nix
@@ -1,6 +1,27 @@
-pkgs:
+pkgs: lib:
 
 rec {
+  addPackageRequires =
+    pkg: packageRequires: addPackageRequiresWhen pkg packageRequires (finalAttrs: previousAttrs: true);
+
+  addPackageRequiresIfOlder =
+    pkg: packageRequires: version:
+    addPackageRequiresWhen pkg packageRequires (
+      finalAttrs: previousAttrs: lib.versionOlder finalAttrs.version version
+    );
+
+  addPackageRequiresWhen =
+    pkg: packageRequires: predicate:
+    pkg.overrideAttrs (
+      finalAttrs: previousAttrs: {
+        packageRequires =
+          if predicate finalAttrs previousAttrs then
+            previousAttrs.packageRequires or [ ] ++ packageRequires
+          else
+            previousAttrs.packageRequires or null;
+      }
+    );
+
   buildWithGit =
     pkg:
     pkg.overrideAttrs (previousAttrs: {
@@ -18,6 +39,34 @@ rec {
 
   fix-rtags = pkg: dontConfigure (externalSrc pkg pkgs.rtags);
 
+  fixRequireHelmCore =
+    pkg:
+    pkg.overrideAttrs (previousAttrs: {
+      postPatch =
+        previousAttrs.postPatch or ""
+        + "\n"
+        + ''
+          substituteInPlace $ename.el \
+            --replace-fail "(require 'helm)" "(require 'helm-core)"
+        '';
+    });
+
+  ignoreCompilationError = pkg: ignoreCompilationErrorWhen pkg (finalAttrs: previousAttrs: true);
+
+  ignoreCompilationErrorIfOlder =
+    pkg: version:
+    ignoreCompilationErrorWhen pkg (
+      finalAttrs: previousAttrs: lib.versionOlder finalAttrs.version version
+    );
+
+  ignoreCompilationErrorWhen =
+    pkg: predicate:
+    pkg.overrideAttrs (
+      finalAttrs: previousAttrs: {
+        ignoreCompilationError = predicate finalAttrs previousAttrs;
+      }
+    );
+
   markBroken =
     pkg:
     pkg.overrideAttrs (previousAttrs: {
@@ -26,13 +75,24 @@ rec {
       };
     });
 
-  mkHome =
-    pkg:
-    pkg.overrideAttrs (previousAttrs: {
-      preInstall =
-        ''
-          HOME=$(mktemp -d)
-        ''
-        + previousAttrs.preInstall or "";
-    });
+  mkHome = pkg: mkHomeWhen pkg (finalAttrs: previousAttrs: true);
+
+  mkHomeIfOlder =
+    pkg: version:
+    mkHomeWhen pkg (finalAttrs: previousAttrs: lib.versionOlder finalAttrs.version version);
+
+  mkHomeWhen =
+    pkg: predicate:
+    pkg.overrideAttrs (
+      finalAttrs: previousAttrs: {
+        preInstall =
+          if predicate finalAttrs previousAttrs then
+            ''
+              HOME=$(mktemp -d)
+            ''
+            + previousAttrs.preInstall or ""
+          else
+            previousAttrs.preInstall or null;
+      }
+    );
 }
diff --git a/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix b/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix
index d61d83bb5aaa..6b3e93aa9754 100644
--- a/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix
+++ b/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix
@@ -30,7 +30,7 @@ in
 
 { lib, pkgs }: variant: self:
 let
-  inherit (import ./lib-override-helper.nix pkgs)
+  inherit (import ./lib-override-helper.nix pkgs lib)
     buildWithGit
     dontConfigure
     externalSrc