[PATCH v4 1/3] classes/base: exclude __CACHED_SOURCE_DATE_EPOCH from task hash

[<daniel.turull@ericsson.com>]

From: Daniel Turull <daniel.turull@ericsson.com>

epochfile_read() memoizes its result into __CACHED_SOURCE_DATE_EPOCH
via d.setVar(), so its runtime value leaks into the basehash of any
task that calls it, causing a "metadata is not deterministic" error
once SDE_FILE is populated.

Exclude it, since it is not meaningful build metadata.

AI-Generated: Uses Kiro with Claude Sonnet 5
Signed-off-by: Daniel Turull <daniel.turull@ericsson.com>
---
This should fix the selftest errors reported by Mathieu
---
 meta/classes-global/base.bbclass | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/meta/classes-global/base.bbclass b/meta/classes-global/base.bbclass
index 9553f00432..01a030399e 100644
--- a/meta/classes-global/base.bbclass
+++ b/meta/classes-global/base.bbclass
@@ -249,6 +249,10 @@ do_unpack[postfuncs] += "create_source_date_epoch_stamp"
 def get_source_date_epoch_value(d):
     return oe.reproducible.epochfile_read(d.getVar('SDE_FILE'), d)
 
+# epochfile_read() memoizes into this variable via d.setVar(), so its
+# runtime value must not leak into any task's hash.
+oe.reproducible.epochfile_read[vardepsexclude] = "__CACHED_SOURCE_DATE_EPOCH"
+
 def get_layers_branch_rev(d):
     revisions = oe.buildcfg.get_layer_revisions(d)
     layers_branch_rev = ["%-20s = \"%s:%s\"" % (r[1], r[2], r[3]) for r in revisions]