libxcrypt: fix cygwin build

Author: corngood

pkgs/development/libraries/libxcrypt/default.nix

@@ -19,6 +19,10 @@ stdenv.mkDerivation (finalAttrs: {
     hash = "sha256-cVE6McAaQovM1TZ6Mv2V8RXW2sUPtbYMd51ceUKuwHE=";
   };
 
+  patches = [
+    ./fix-symver-on-non-elf.patch
+  ];
+
   # this could be accomplished by updateAutotoolsGnuConfigScriptsHook, but that causes infinite recursion
   # necessary for FreeBSD code path in configure
   postPatch = ''
@@ -36,15 +40,16 @@ stdenv.mkDerivation (finalAttrs: {
     "--disable-failure-tokens"
     # required for musl, android, march=native
     "--disable-werror"
-  ];
+  ]
+  ++ lib.optional stdenv.hostPlatform.isCygwin "--disable-symvers";
 
   makeFlags =
     let
       lld17Plus = stdenv.cc.bintools.isLLVM && lib.versionAtLeast stdenv.cc.bintools.version "17";
     in
     [ ]
     # fixes: can't build x86_64-w64-mingw32 shared library unless -no-undefined is specified
-    ++ lib.optionals stdenv.hostPlatform.isWindows [ "LDFLAGS+=-no-undefined" ]
+    ++ lib.optionals stdenv.hostPlatform.isPE [ "LDFLAGS+=-no-undefined" ]
 
     # lld 17 sets `--no-undefined-version` by default and `libxcrypt`'s
     # version script unconditionally lists legacy compatibility symbols, even

pkgs/development/libraries/libxcrypt/fix-symver-on-non-elf.patch

@@ -0,0 +1,42 @@
+From c3afeaaa5a715380caa7209d4596ff2b8aeb73a0 Mon Sep 17 00:00:00 2001
+From: David McFarland <corngood@gmail.com>
+Date: Thu, 11 Sep 2025 16:58:06 -0300
+Subject: [PATCH] cygwin: fix symver
+
+---
+ lib/crypt-port.h | 8 ++++++++
+ 1 file changed, 8 insertions(+)
+
+diff --git a/lib/crypt-port.h b/lib/crypt-port.h
+index a707939..25ad957 100644
+--- a/lib/crypt-port.h
++++ b/lib/crypt-port.h
+@@ -213,6 +213,7 @@ extern size_t strcpy_or_abort (void *dst, size_t d_size, const void *src);
+ 
+ /* Starting with GCC 10, we can use the symver attribute, which is also
+    needed at the point we decide to enable link-time optimization.  */
++#ifdef __ELF__
+ # if defined HAVE_FUNC_ATTRIBUTE_SYMVER
+ 
+ /* Set the symbol version for EXTNAME, which uses INTNAME as its
+@@ -234,10 +235,17 @@ extern size_t strcpy_or_abort (void *dst, size_t d_size, const void *src);
+ 
+ # endif
+ 
++#else
++#define symver_set(...) symver_nop()
++#endif
++
+ #else
+ # error "Don't know how to do symbol versioning with this compiler"
+ #endif
+ 
++
++
++
+ /* A construct with the same syntactic role as the expansion of symver_set,
+    but which does nothing.  */
+ #define symver_nop() __asm__ ("")
+-- 
+2.50.1
+