4 files changed, 13 insertions, 13 deletions
diff --git a/pkgs/development/tools/parsing/flex/2.5.35.nix b/pkgs/development/tools/parsing/flex/2.5.35.nix
index b2245ff9c9b92..ec2c9eeb2d1c6 100644
--- a/pkgs/development/tools/parsing/flex/2.5.35.nix
+++ b/pkgs/development/tools/parsing/flex/2.5.35.nix
@@ -16,10 +16,10 @@ stdenv.mkDerivation {
 
   propagatedBuildInputs = [ m4 ];
 
-  preConfigure = lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
-    "ac_cv_func_malloc_0_nonnull=yes"
-    "ac_cv_func_realloc_0_nonnull=yes"
-  ];
+  preConfigure = lib.optionalString (stdenv.hostPlatform != stdenv.buildPlatform) ''
+    ac_cv_func_malloc_0_nonnull=yes
+    ac_cv_func_realloc_0_nonnull=yes
+  '';
 
   doCheck = false; # fails 2 out of 46 tests
 
diff --git a/pkgs/development/tools/parsing/flex/2.6.1.nix b/pkgs/development/tools/parsing/flex/2.6.1.nix
index cc0ecb148c445..aeb141649772d 100644
--- a/pkgs/development/tools/parsing/flex/2.6.1.nix
+++ b/pkgs/development/tools/parsing/flex/2.6.1.nix
@@ -18,10 +18,10 @@ stdenv.mkDerivation {
 
   propagatedBuildInputs = [ m4 ];
 
-  preConfigure = lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
-    "ac_cv_func_malloc_0_nonnull=yes"
-    "ac_cv_func_realloc_0_nonnull=yes"
-  ];
+  preConfigure = lib.optionalString (stdenv.hostPlatform != stdenv.buildPlatform) ''
+    ac_cv_func_malloc_0_nonnull=yes
+    ac_cv_func_realloc_0_nonnull=yes
+  '';
 
   postConfigure = lib.optionalString (stdenv.isDarwin || stdenv.isCygwin) ''
     sed -i Makefile -e 's/-no-undefined//;'
diff --git a/pkgs/development/tools/parsing/flex/default.nix b/pkgs/development/tools/parsing/flex/default.nix
index 0bc26db575045..e0895bab68d8a 100644
--- a/pkgs/development/tools/parsing/flex/default.nix
+++ b/pkgs/development/tools/parsing/flex/default.nix
@@ -33,10 +33,10 @@ stdenv.mkDerivation rec {
   buildInputs = [ bison ];
   propagatedBuildInputs = [ m4 ];
 
-  preConfigure = lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
-    "export ac_cv_func_malloc_0_nonnull=yes"
-    "export ac_cv_func_realloc_0_nonnull=yes"
-  ];
+  preConfigure = lib.optionalString (stdenv.hostPlatform != stdenv.buildPlatform) ''
+    export ac_cv_func_malloc_0_nonnull=yes
+    export ac_cv_func_realloc_0_nonnull=yes
+  '';
 
   postConfigure = lib.optionalString (stdenv.isDarwin || stdenv.isCygwin) ''
     sed -i Makefile -e 's/-no-undefined//;'
diff --git a/pkgs/development/tools/parsing/ragel/default.nix b/pkgs/development/tools/parsing/ragel/default.nix
index 6bbcf36cd2c22..c23b352deceaf 100644
--- a/pkgs/development/tools/parsing/ragel/default.nix
+++ b/pkgs/development/tools/parsing/ragel/default.nix
@@ -15,7 +15,7 @@ let
 
       buildInputs = lib.optional build-manual [ transfig ghostscript tex ];
 
-      preConfigure = lib.optional build-manual ''
+      preConfigure = lib.optionalString build-manual ''
         sed -i "s/build_manual=no/build_manual=yes/g" DIST
       '';