I have setup a testing cell to stress test OpenAFS.  When running one
of that tests, diffing the sources of kernel.  I get some errors if I
do not add the --touch flag to the tar xf -

xz -dc t.tar.xz | tar --touch -xf -

It should work with just:

xz -dc t.tar.xz | tar -xf -


Example:

xzcat t.tar.xz | tar xf -
tar: linux-5.0/Documentation/Changes: Cannot utime: Operation not permitted
tar: linux-5.0/arch/arm/boot/dts/sun8i-a23-ippo-q8h-v1.2.dts: Cannot utime: Operation not permitted
tar: linux-5.0/arch/arm/boot/dts/sun8i-a23-ippo-q8h-v5.dts: Cannot utime: Operation not permitted
tar: linux-5.0/arch/arm/boot/dts/sun8i-a33-et-q8-v1.6.dts: Cannot utime: Operation not permitted
tar: linux-5.0/arch/arm/boot/dts/sun8i-a33-ippo-q8h-v1.2.dts: Cannot utime: Operation not permitted
(...)


Kind regards
Jose M Calhariz