When there is a relative symlink in the layer, for example:
symA -> ../out/of/layer/file
symA will be invalid fater copied, it would be invalid from build time
if it points to a relative path, and would be invalid after extracted
the sdk if it points to a absolute py. Dereference symlink when copy
will fix the problem.
Use tar rather than shutil.copytree() to copy is because:
1) shutil.copytree(symlinks=Fasle) has bugs when dereference symlinks:
https://bugs.python.org/issue21697
And Ubunutu 1404 doesn't upgrade python3 to fix the problem.
2) shutil.copytree(symlinks=False) raises errors when there is a invalid
symlink, and tar just prints a warning, tar is preferred here since
the real world is unpredicatable
3) tar is faster than shutil.copytree() as said by oe.path.copytree()
So use tar to copy.
Signed-off-by: Robert Yang <liezhi.yang@windriver.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
