From d8bcc674c4bac48aedc7f421fcc2c3d0487a150a Mon Sep 17 00:00:00 2001
From: Jan Tojnar <jtojnar@gmail.com>
Date: Thu, 27 Jan 2022 17:20:17 +0100
Subject: [PATCH] gdal: fix build with latest poppler

Poppler 22.01.0 requires std=c++17:

https://gitlab.freedesktop.org/poppler/poppler/-/merge_requests/1027
---
 pkgs/development/libraries/gdal/default.nix | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/libraries/gdal/default.nix b/pkgs/development/libraries/gdal/default.nix
index 124c0a48cde6..3e5ae303dd77 100644
--- a/pkgs/development/libraries/gdal/default.nix
+++ b/pkgs/development/libraries/gdal/default.nix
@@ -62,7 +62,11 @@ stdenv.mkDerivation rec {
 
   hardeningDisable = [ "format" ];
 
-  CXXFLAGS = "-fpermissive";
+  CXXFLAGS = lib.concatStringsSep " " [
+    "-fpermissive"
+    # poppler uses std::optional
+    "-std=c++17"
+  ];
 
   # - Unset CC and CXX as they confuse libtool.
   # - teach gdal that libdf is the legacy name for libhdf