[gnome-continuous-yocto/gnomeostree-3.28-rocko: 7908/8267] systemd-serialtty: allow empty package

[Emmanuele Bassi <ebassi src gnome org>]

commit c1d3dbb5bdbea42c3f4b4706872bd2444e850c7c
Author: Chen Qi <Qi Chen windriver com>
Date:   Tue Sep 26 16:41:38 2017 +0800

    systemd-serialtty: allow empty package
    
    If SERIAL_CONSOLES is set to empty for some reason, we would have rootfs
    failure like below.
    
      - nothing provides systemd-serialgetty needed by systemd-1:234-r0.core2_64
    
    This is because systemd-serialgetty package is not generated when
    SERIAL_CONSOLES is empty.
    
    Set ALLOW_EMPTY to "1" for this recipe to allow for generation of empty
    systemd-serialgetty package to avoid the above error.
    
    (From OE-Core rev: abf2e9526a11bcb51b71b90a7b76bd33af656494)
    
    Signed-off-by: Chen Qi <Qi Chen windriver com>
    Signed-off-by: Richard Purdie <richard purdie linuxfoundation org>

 meta/recipes-core/systemd/systemd-serialgetty.bb |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/meta/recipes-core/systemd/systemd-serialgetty.bb 
b/meta/recipes-core/systemd/systemd-serialgetty.bb
index 74b5986..d934716 100644
--- a/meta/recipes-core/systemd/systemd-serialgetty.bb
+++ b/meta/recipes-core/systemd/systemd-serialgetty.bb
@@ -48,3 +48,5 @@ python () {
     if not bb.utils.contains ('DISTRO_FEATURES', 'systemd', True, False, d):
         raise bb.parse.SkipPackage("'systemd' not in DISTRO_FEATURES")
 }
+
+ALLOW_EMPTY_${PN} = "1"