From 0c8a51c7d28befa49e596421de22c0b4fef100f0 Mon Sep 17 00:00:00 2001
From: Marius Bakke <mbakke@fastmail.com>
Date: Thu, 21 May 2020 22:09:21 +0200
Subject: [PATCH] gnu: cogl: Fix build with Mesa 20.

* gnu/packages/gnome.scm (cogl)[arguments]: Add phase to adjust header includes.
---
 gnu/packages/gnome.scm | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/gnu/packages/gnome.scm b/gnu/packages/gnome.scm
index 938efbcdf3..e0e1ed1804 100644
--- a/gnu/packages/gnome.scm
+++ b/gnu/packages/gnome.scm
@@ -4486,6 +4486,17 @@ (define-public cogl
                                               "/lib/libGL.so"))
        #:phases
        (modify-phases %standard-phases
+         (add-after 'unpack 'fix-build-with-mesa-20
+           (lambda _
+             ;; Work around a problem with Mesa 20 where some macros used by
+             ;; Cogl went missing from eglext.h.  This can likely be removed
+             ;; for newer versions of Cogl or Mesa.
+             ;; https://gitlab.gnome.org/GNOME/cogl/-/merge_requests/19
+             (substitute* '("configure"
+                            "cogl/winsys/cogl-winsys-egl-kms.c")
+               (("#include <EGL/eglext.h>" all)
+                (string-append all "\n#include <EGL/eglmesaext.h>\n")))
+             #t))
          (add-before 'check 'start-xorg-server
                      (lambda* (#:key tests? inputs #:allow-other-keys)
                        (if tests?