meson: fix cross-compilation with vala

srcpkgs/meson/patches/fix-cross-vala.patch

@@ -0,0 +1,47 @@
+From 77c3e6a4aaed07e626f4bf4deb7eb66e0f03a33d Mon Sep 17 00:00:00 2001
+From: James Westman <flyingpimonster@flyingpimonster.net>
+Date: Mon, 24 Jun 2019 12:04:12 -0500
+Subject: [PATCH] Fix two errors when cross-compiling with Vala
+
+- AttributeError: 'ValaCompiler' object has no attribute 'get_program_dirs'
+
+  Fixed by adding a `get_program_dirs()` function to the base Compiler
+  class, to match `get_library_dirs()`
+
+- KeyError: 'vala_COMPILER'
+
+  Fixed by creating the Vala compile rules for all machines, not just
+  the build machine.
+---
+ mesonbuild/backend/ninjabackend.py | 3 +--
+ mesonbuild/compilers/compilers.py  | 3 +++
+ 2 files changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
+index a454e6ab5f..b830e377e4 100644
+--- mesonbuild/backend/ninjabackend.py
++++ mesonbuild/backend/ninjabackend.py
+@@ -1653,8 +1653,7 @@ def generate_compile_rule_for(self, langname, compiler):
+                 self.generate_cs_compile_rule(compiler)
+             return
+         if langname == 'vala':
+-            if self.environment.machines.matches_build_machine(compiler.for_machine):
+-                self.generate_vala_compile_rules(compiler)
++            self.generate_vala_compile_rules(compiler)
+             return
+         if langname == 'rust':
+             self.generate_rust_compile_rules(compiler)
+diff --git a/mesonbuild/compilers/compilers.py b/mesonbuild/compilers/compilers.py
+index 5855de71c8..86c1e33407 100644
+--- mesonbuild/compilers/compilers.py
++++ mesonbuild/compilers/compilers.py
+@@ -1117,6 +1117,9 @@ def find_library(self, *args, **kwargs):
+     def get_library_dirs(self, *args, **kwargs):
+         return ()
+ 
++    def get_program_dirs(self, *args, **kwargs):
++        return ()
++
+     def has_multi_arguments(self, args, env) -> Tuple[bool, bool]:
+         raise EnvironmentException(
+             'Language {} does not support has_multi_arguments.'.format(

srcpkgs/meson/template

@@ -1,7 +1,7 @@
 # Template file for 'meson'
 pkgname=meson
 version=0.51.0
-revision=1
+revision=2
 archs=noarch
 build_style=python3-module
 pycompile_module="mesonbuild"