Added Debian multilib support.

meson.py

@@ -42,7 +42,7 @@ else:
 
 parser.add_option('--prefix', default=def_prefix, dest='prefix',
                   help='the installation prefix (default: %default)')
-parser.add_option('--libdir', default='lib', dest='libdir',
+parser.add_option('--libdir', default=mesonlib.default_libdir(), dest='libdir',
                   help='the installation subdir of libraries (default: %default)')
 parser.add_option('--bindir', default='bin', dest='bindir',
                   help='the installation subdir of executables (default: %default)')

mesonlib.py

@@ -86,3 +86,9 @@ def version_compare(vstr1, vstr2):
     varr1 = [int(x) for x in vstr1.split('.')]
     varr2 = [int(x) for x in vstr2.split('.')]
     return cmpop(varr1, varr2)
+
+def default_libdir():
+    if os.path.isfile('/etc/debian_version'):
+        archpath = subprocess.check_output(['dpkg-architecture', '-qDEB_HOST_MULTIARCH']).decode().strip()
+        return 'lib/' + archpath
+    return 'lib'