fix #21521

pkgs/development/libraries/libpaper/default.nix

@@ -9,6 +9,25 @@ stdenv.mkDerivation rec {
     sha256 = "0zhcx67afb6b5r936w5jmaydj3ks8zh83n9rm5sv3m3k8q8jib1q";
   };
 
+  # The configure script of libpaper is buggy: it uses AC_SUBST on a headerfile
+  # to compile sysconfdir into the library. Autoconf however defines sysconfdir
+  # as "${prefix}/etc", which is not expanded by AC_SUBST so libpaper will look
+  # for config files in (literally, without expansion) '${prefix}/etc'. Manually
+  # setting sysconfdir fixes this issue.
+  preConfigure = ''
+    configureFlagsArray+=(
+      "--sysconfdir=$out/etc"
+    )
+  '';
+
+  # Set the default paper to letter (this is what libpaper uses as default as well,
+  # if you call getdefaultpapername()).
+  # The user can still override this with the PAPERCONF environment variable.
+  postInstall = ''
+    mkdir -p $out/etc
+    echo letter > $out/etc/papersize
+  '';
+
   meta = {
     description = "Library for handling paper characteristics";
     homepage = "http://packages.debian.org/unstable/source/libpaper";