Set EXTERNAL_BUILD_TIMESTAMP from SOURCE_DATE_EPOCH
to make the package build reproducible by default without
everyone having to discover the custom variable.
This code assigns the plain integer to keep the code simple.
Otherwise we would have to deal with differences between GNU date
and BSD date or include extra build deps like perl or python.
Set
EXTERNAL_BUILD_TIMESTAMPfromSOURCE_DATE_EPOCHto make the package build reproducible by default without everyone having to discover the custom variable.See https://reproducible-builds.org/ for why this is good and https://reproducible-builds.org/specs/source-date-epoch/ for the definition of this variable.
This code assigns the plain integer to keep the code simple. Otherwise we would have to deal with differences between GNU date and BSD date or include extra build deps like perl or python.