bitbake: fetch2: use relative symlinks for anything pulled from PREMIRRORS

try_mirror_url() creates a symlink named as the original file to make
everything look like files specified in SRC_URI were downloaded from
their original location. The link is however created as an absolute
reference, this makes DL_DIR non-relocatable. This also causes issues
with the Isar project since it bind mounts DL_DIR to /downloads to
perform some of its build tasks in a chrooted environment (rendering
all symbolic links from DL_DIR invalid). Modify ensure_symlink() to
take an optional "relative" argument and have that function use
os.path.relpath() to produce a relative symlink.

(Bitbake rev: 481e66ea8fc2fc91903127d66b0f1b0fe86baedb)

Signed-off-by: Cedric Hombourger <Cedric_Hombourger@mentor.com>
Cc: Chris Larson <Chris_Larson@mentor.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/bitbake/lib/bb/fetch2/__init__.py b/bitbake/lib/bb/fetch2/__init__.py
index 07b7ae41b4..290773072f 100644
--- a/bitbake/lib/bb/fetch2/__init__.py
+++ b/bitbake/lib/bb/fetch2/__init__.py
@@ -1021,7 +1021,8 @@ def try_mirror_url(fetch, origud, ud, ld, check = False):
                     origud.method.build_mirror_data(origud, ld)
             return origud.localpath
         # Otherwise the result is a local file:// and we symlink to it
-        ensure_symlink(ud.localpath, origud.localpath)
+        ensure_symlink(ud.localpath, origud.localpath, relative=True)
+
         update_stamp(origud, ld)
         return ud.localpath
 
@@ -1055,7 +1056,7 @@ def try_mirror_url(fetch, origud, ud, ld, check = False):
             bb.utils.unlockfile(lf)
 
 
-def ensure_symlink(target, link_name):
+def ensure_symlink(target, link_name, relative=False):
     if not os.path.exists(link_name):
         if os.path.islink(link_name):
             # Broken symbolic link
@@ -1066,6 +1067,8 @@ def ensure_symlink(target, link_name):
         # same time, in which case we do not want the second task to
         # fail when the link has already been created by the first task.
         try:
+            if relative is True:
+                target = os.path.relpath(target, os.path.dirname(link_name))
             os.symlink(target, link_name)
         except FileExistsError:
             pass