[nautilus-python] Allow to override build date

[Adam Plumb <adamplumb src gnome org>]

commit bc4e6cb96f3b5185b4c63bd7904b6408207d2687
Author: Bernhard M. Wiedemann <bwiedemann suse de>
Date:   Wed Jun 19 20:47:43 2019 -0400

    Allow to override build date

 docs/Makefile.am | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/docs/Makefile.am b/docs/Makefile.am
index 3b2a0b7..d3ad7ba 100644
--- a/docs/Makefile.am
+++ b/docs/Makefile.am
@@ -74,7 +74,7 @@ REFERENCE_DEPS =      \
 if ENABLE_GTK_DOC
 
 reference/builddate.xml: $(REFERENCE_DEPS)
-       $(PYTHON) -c 'import datetime; print(datetime.date.today())' > $@
+       $(PYTHON) -c "import datetime; import os; import time; 
print(datetime.datetime.utcfromtimestamp(int(os.environ.get('SOURCE_DATE_EPOCH', time.time()))).date())" > $@
 
 $(HTML_DATA): $(REFERENCE_DEPS) reference/builddate.xml
        $(GTKDOC_MKHTML) \