[PATCH v2 1/3] migration-guides: systemd.bbclass do not add Also services for 5.2

[Adrian Freihofer <adrian.freihofer@gmail.com>]

Covers the chagnes introduced by commit
https://git.yoctoproject.org/poky/commit/?id=efa5f65c2214239ed7aaf7bd8998683e755c5660

Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>
---
 .../migration-guides/migration-5.2.rst        | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/documentation/migration-guides/migration-5.2.rst b/documentation/migration-guides/migration-5.2.rst
index cb70e19da..b18ae30d9 100644
--- a/documentation/migration-guides/migration-5.2.rst
+++ b/documentation/migration-guides/migration-5.2.rst
@@ -74,6 +74,25 @@ systemd changes
    As a consequence, the ``systemd`` recipe no longer contains the ``usrmerge``
    :term:`PACKAGECONFIG` option as it is now implied by default.
 
+-  ``systemd.bbclass``: If a systemd service file had referred to other service
+   files by starting them as
+   `Also <https://www.freedesktop.org/software/systemd/man/latest/systemd.unit.html#Also=>`__,
+   the other service files were automatically added to the :term:`FILES` variable of
+   the same package. Example: 
+
+   a.service contains::
+
+      [Install]
+      Also=b.service
+
+   If a.service is packaged in package A, b.service is automatically packaged
+   into package A as well. This happens even if b.service is explicitly added
+   to package B using FILES and :term:`SYSTEMD_SERVICE` variables.
+   This prevents such services from being packaged into different packages.
+   Therefore, this automatic behavior has been removed for service files (but
+   not for socket files).
+   Now all service files must be explicitly added to :term:`FILES`.
+
 Recipe changes
 ~~~~~~~~~~~~~~
 
-- 
2.47.1