[libsoup] meson: make sure tests run against the built library

[Claudio Saavedra <csaavedra src gnome org>]

commit 150cef0be29f54b6111dc0925ad5ea24042a87d5
Author: Claudio Saavedra <csaavedra igalia com>
Date:   Thu Sep 20 15:25:35 2018 +0300

    meson: make sure tests run against the built library
    
    For some reason meson is honoring the LD_LIBRARY_PATH when running
    the tests, so the built library is not tested. Add this for now
    to work it around.
    
    See https://github.com/mesonbuild/meson/issues/4228

 tests/meson.build | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/tests/meson.build b/tests/meson.build
index afd97566..8176f29b 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -96,6 +96,8 @@ endif
 env = environment()
 env.set('G_TEST_SRCDIR', meson.current_source_dir())
 env.set('G_TEST_BUILDDIR', meson.current_build_dir())
+# See https://github.com/mesonbuild/meson/issues/4228 for the workaround below
+env.prepend('LD_LIBRARY_PATH', meson.build_root() + '/libsoup')
 env.set('G_DEBUG', 'gc-friendly')
 env.set('MALLOC_CHECK_', '2')
 # This is set by Meson if empty