[bug#38073] [PATCH] gnu: grantlee: Fix build for Qt 5.12.

[Hartmut Goebel]

Build using gnu++11 standard.

* gnu/packages/qt.scm(grantlee)[argument]<configure-flags>: New
  element.
---
 gnu/packages/qt.scm | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/qt.scm b/gnu/packages/qt.scm
index 8928c1ddd4..0ef879678f 100644
--- a/gnu/packages/qt.scm
+++ b/gnu/packages/qt.scm
@@ -100,7 +100,8 @@
        ("qtscript" ,qtscript)))
     (build-system cmake-build-system)
     (arguments
-     `(#:phases
+     `(#:configure-flags '("-DCMAKE_CXX_STANDARD=11")
+       #:phases
        (modify-phases %standard-phases
          (add-after 'unpack 'delete-broken-tests
            (lambda _
-- 
2.21.0