Fix for double-conversion when using pkgsStatic

Author: hamishmack

test/modules.nix

@@ -1,4 +1,5 @@
 [{
+  package-keys = ["HsOpenSSL" "libsodium" "double-conversion"];
   # See https://github.com/haskell-cryptography/HsOpenSSL/issues/95
   packages.HsOpenSSL.ghcOptions = ["-optc=-Wno-incompatible-pointer-types"];
 }
@@ -7,4 +8,15 @@
   packages.libsodium.configureFlags = [ "--c2hs-option=--cppopts=-D_Null_unspecified=" ];
   packages.libsodium.components.library.hardeningDisable = ["fortify"];
 })
+
+({pkgs, lib, ...}: lib.mkIf pkgs.stdenv.hostPlatform.isStatic {
+  packages.double-conversion.ghcOptions = [
+    # stop putting U __gxx_personality_v0 into the library!
+    "-optcxx-fno-rtti"
+    "-optcxx-fno-exceptions"
+    # stop putting U __cxa_guard_release into the library!
+    "-optcxx-std=gnu++98"
+    "-optcxx-fno-threadsafe-statics"
+  ];
+})
 ]