SSTATE MIRRORS only partly working?

[Gary Thomas <gary@mlbassoc.com>]

Trying my SSTATE_MIRROR test with a recent Poky tree, I find
that for the most part, it doesn't work as expected (at least
not as I expect).

Here's my test setup:
   * Create a complete build
     % . /local/poky/oe-init-build-env /local/build_orig
     % bitbake SOME-RECIPE
   * Use that build for the SSTATE_MIRROR
     % . /local/poky/oe-init-build-env /local/build_test
     -- edit conf/local.conf to have these lines:
         SSTATE_MIRRORS ?= "\
         file://.* file:///local/build_orig/sstate-cache/"
     % bitbake SOME-RECIPE

What I find is that this second build is rebuilding a lot of
things, most strikingly the -native packages.  Looking into
it, I see that the original build creates
   sstate-pseudo-native-i686-linux-1.0-r0-i686-2-999fef0f7f260a6672c3678a831fa36f_populate-sysroot.tgz
but when the test build runs, it's looking for
   sstate-pseudo-native-i686-linux-1.0-r0-i686-2-feb469d055bfc4f32074e7e9499eaf22_populate-sysroot.tgz

Odd, but it's not always different, for example
   sstate-perl-native-i686-linux-5.12.3-r2-i686-2-75d16ce5b7c945262d819c24f59d1c9f_populate-sysroot.tgz
is the same in both builds and is thus shared.

Note that nothing else has changed, other than the process above.
The COREBASE tree is identical/untouched.

Am I missing something here?

Thanks

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------