perl-YAML-Syck: build with gnu17

newer not supported by upstream

perl-YAML-Syck/PKGBUILD

@@ -3,7 +3,7 @@
 _realname=YAML-Syck
 pkgname=perl-YAML-Syck
 pkgver=1.34
-pkgrel=5
+pkgrel=6
 pkgdesc="Fast, lightweight YAML loader and dumper"
 arch=('i686' 'x86_64')
 url="https://metacpan.org/release/YAML-Syck"
@@ -24,7 +24,9 @@ prepare() {
 
 build() {
   cd YAML-Syck-${pkgver}
-  perl Makefile.PL INSTALLDIRS=vendor
+
+  # https://github.com/cpan-authors/YAML-Syck/issues/61
+  perl Makefile.PL INSTALLDIRS=vendor OPTIMIZE="$CFLAGS -std=gnu17"
   make
 }