sasquatch: fix build for gcc 15

GCC 15 defaults to C23, so the interpretation of a function with an
empty parameter list becomes that it has no parameters instead of
ambiguous. Thus, we include a patch to add missing parameters to
function definitions.

pkgs/by-name/sa/sasquatch/gcc15-fix-prototypes.patch

@@ -0,0 +1,22 @@
+diff --git a/squashfs-tools/unsquashfs.c b/squashfs-tools/unsquashfs.c
+index ed5096b32d..adb6a91c7e 100644
+--- a/squashfs-tools/unsquashfs.c
++++ b/squashfs-tools/unsquashfs.c
+@@ -146,7 +146,7 @@
+ 
+ #define MAX_LINE 16384
+ 
+-void sigwinch_handler()
++void sigwinch_handler(int _signal)
+ {
+ 	struct winsize winsize;
+ 
+@@ -160,7 +160,7 @@
+ }
+ 
+ 
+-void sigalrm_handler()
++void sigalrm_handler(int _signal)
+ {
+ 	rotate = (rotate + 1) % 4;
+ }

pkgs/by-name/sa/sasquatch/package.nix

@@ -23,7 +23,12 @@ let
       hash = "sha256-4Mltt0yFt4oh9hsrHL8/ch5n7nZYiXIJ1UgLktPvlKQ=";
     };
 
-    patches = lib.optional stdenv.hostPlatform.isDarwin ./darwin.patch;
+    patches = [
+      # Fix build for GCC 15/C23 by adding parameters to unsquashfs signal
+      # handlers instead of relying on an empty parameter list.
+      ./gcc15-fix-prototypes.patch
+    ]
+    ++ lib.optional stdenv.hostPlatform.isDarwin ./darwin.patch;
 
     strictDeps = true;
     nativeBuildInputs = [ which ];