If you need/want to support dpkg versions earlier than 1.18.8: export SOURCE_DATE_EPOCH ?= $(shell dpkg-parsechangelog -SDate | date -f- +%s) If none of the above options are good (you should have a ‘‘very good reason’’) then package maintainers may set and export this variable manually in debian/rules:Įxport SOURCE_DATE_EPOCH ?= $(shell dpkg-parsechangelog -STimestamp) With dpkg >= 1.18.8 (Bug:824572) you can either include /usr/share/dpkg/pkg-info.mk or include /usr/share/dpkg/default.mk. One exception is if your debian/rules needs this variable in non-debhelper parts, in which case you can try (3) or (4).įor packages using CDBS, versions >= 0.4.131 (Bug:794241) exports this variable during builds, so no changes are needed. the same as the output of dpkg-parsechangelog -SDate.įor packages using debhelper, versions >= 9.20151004 (Bug:791823) exports this variable during builds, so you probably don’t need to change anything.

In Debian, this is automatically set to the same time as the latest entry in debian/changelog, i.e. See Standard Environment Variables for more detailed discussion of the rationales behind this mechanism.īelow we also have more detailed discussion about this specific variable, as well as documentation on history and alternative proposals. Please read our SOURCE_DATE_EPOCH specification for details. If you find that it’s ideal for your use-case, please feel free to jump straight to our published specification.

In practice SOURCE_DATE_EPOCH specifies the last modification of something, usually the source code, (measured) in seconds since the Unix epoch, which is January 1st 1970, 00:00:00 UTC.īefore implementing this, you should scan through our checklist to see if you can avoid implementing it. SOURCE_DATE_EPOCH is a standardised environment variable that distributions can set centrally and have build tools consume this in order to produce reproducible output.

Linux time style format epoh