externalsrc: use shared stamp directory if B=S

We have a common build directory for all target architectures if
externalsrc is used and ${B}=${S}. In this case we also need to have a
common stamp directory. The reason is that e.g. changing MACHINE will
basically "invalidate" the artefacts in ${B} (wrt. to the new MACHINE)
but old stamp files with matching hashes from an earlier build might be
available in the machine-specific stamps directory and tasks would not
be correctly re-run.

Previous attempt in f44f12af346888bdeb3ae01a275cb5dd4396b505 to handle
this correctly was faulty as it threw some spurious warnings and caused
do_configure to be re-run in every build if that would not be necessary.

[YOCTO #8950]
[YOCTO #9237]

Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/meta/classes/externalsrc.bbclass b/meta/classes/externalsrc.bbclass
index 0ec338c660..d3cede2b68 100644
--- a/meta/classes/externalsrc.bbclass
+++ b/meta/classes/externalsrc.bbclass
@@ -92,15 +92,13 @@ python () {
         d.appendVar('RM_WORK_EXCLUDE', ' ' + d.getVar('PN', True))
 
         # If B=S the same builddir is used even for different architectures.
-        # Thus, use a shared CONFIGURESTAMPFILE so that change of do_configure
-        # task hash is correctly detected if e.g. MACHINE changes. In addition,
-        # do_configure needs to depend on the stamp file so that the task is
-        # re-run when the stamp was changed since the last run on this
-        # architecture.
+        # Thus, use a shared CONFIGURESTAMPFILE and STAMP directory so that
+        # change of do_configure task hash is correctly detected and stamps are
+        # invalidated if e.g. MACHINE changes.
         if d.getVar('S', True) == d.getVar('B', True):
             configstamp = '${TMPDIR}/work-shared/${PN}/${EXTENDPE}${PV}-${PR}/configure.sstate'
             d.setVar('CONFIGURESTAMPFILE', configstamp)
-            d.setVarFlag('do_configure', 'file-checksums', configstamp + ':True')
+            d.setVar('STAMP', '${STAMPS_DIR}/work-shared/${PN}/${EXTENDPE}${PV}-${PR}')
 }
 
 python externalsrc_configure_prefunc() {