| Message ID | 20170321000712.26500-2-arnout@mind.be |
|---|---|
| State | Accepted |
| Headers | show |
Hello, On Tue, 21 Mar 2017 01:06:57 +0100, Arnout Vandecappelle (Essensium/Mind) wrote: > On most distros, the tar format defaults to GNU. However, at build time > the default format may be changed to posix. Also, future versions of > tar will default to posix. > > Since we want the tarballs created by the git download method to be > reproducible (so their hash can be checked), we should explicitly > specify the format. Since existing tarballs on sources.buildroot.org > use the GNU format, and also the existing hashes in the *.hash files > are based on GNU format tarballs, we use the GNU format. > > In addition, the Posix format encodes atime and ctime as well as mtime, > but tar offers no option like --mtime to override them. In the GNU > format, atime and ctime are only encoded if the --incremental option is > given. > > Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be> > Cc: Peter Seiderer <ps.report@gmx.net> > --- > Peter, can you test if this solves the issue for you? > --- > support/download/git | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) Applied to master, thanks. We require tar 1.17 at least, and I checked that tar 1.17 supports --format=gnu. Thomas
>>>>> "Arnout" == Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be> writes: > On most distros, the tar format defaults to GNU. However, at build time > the default format may be changed to posix. Also, future versions of > tar will default to posix. > Since we want the tarballs created by the git download method to be > reproducible (so their hash can be checked), we should explicitly > specify the format. Since existing tarballs on sources.buildroot.org > use the GNU format, and also the existing hashes in the *.hash files > are based on GNU format tarballs, we use the GNU format. > In addition, the Posix format encodes atime and ctime as well as mtime, > but tar offers no option like --mtime to override them. In the GNU > format, atime and ctime are only encoded if the --incremental option is > given. > Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be> > Cc: Peter Seiderer <ps.report@gmx.net> > --- > Peter, can you test if this solves the issue for you? Committed to 2017.02.x, thanks.
diff --git a/support/download/git b/support/download/git index 7921411835..056057c700 100755 --- a/support/download/git +++ b/support/download/git @@ -94,6 +94,8 @@ popd >/dev/null # Generate the archive, sort with the C locale so that it is reproducible find "${basename}" -not -type d >"${basename}.list" LC_ALL=C sort <"${basename}.list" >"${basename}.list.sorted" -tar cf - --numeric-owner --owner=0 --group=0 --mtime="${date}" \ +# Create GNU-format tarballs, since that's the format of the tarballs on +# sources.buildroot.org and used in the *.hash files +tar cf - --numeric-owner --owner=0 --group=0 --mtime="${date}" --format=gnu \ -T "${basename}.list.sorted" >"${output}.tar" gzip -n <"${output}.tar" >"${output}"
On most distros, the tar format defaults to GNU. However, at build time the default format may be changed to posix. Also, future versions of tar will default to posix. Since we want the tarballs created by the git download method to be reproducible (so their hash can be checked), we should explicitly specify the format. Since existing tarballs on sources.buildroot.org use the GNU format, and also the existing hashes in the *.hash files are based on GNU format tarballs, we use the GNU format. In addition, the Posix format encodes atime and ctime as well as mtime, but tar offers no option like --mtime to override them. In the GNU format, atime and ctime are only encoded if the --incremental option is given. Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be> Cc: Peter Seiderer <ps.report@gmx.net> --- Peter, can you test if this solves the issue for you? --- support/download/git | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)