Christian Franke wrote:
> A small step towards reproducible packaging...
>
> Currently only tested with upcoming smartmontools package - contains 
> only exe, man, doc files (no dll, lib, ...). Multiple cygport runs 
> produce binary identical distribution tarballs if SOURCE_DATE_EPOCH 
> (from the past) is specified in the cygport file.
>

A slightly enhanced patch is attached. For .gz files, 'gzip -n' is now 
used as suggested.


Result from a test with the cygwin-3.4.8-1 source package:

These two lines were added to cygwin.cygport:

  VERSION="3.4.8"
  RELEASE="1"
+export SOURCE_DATE_EPOCH=$(date -d '2023-08-18 UTC' +%s)
+export TZ=UTC

(TZ=UTC is a workaround for a minor bug in SOURCE_DATE_EPOCH handling of 
gropdf)

These distribution files are always identical:
- cygwin-3.4.8-1-src.tar.xz
- cygwin-doc-3.4.8-1.tar.xz

These individual files differ if the build-path of multiple test-builds 
is always the same:

- usr/bin/cygwin1.dll:
-- Contains a build timestamp not based on '__DATE__ __TIME__'. Could be 
easily addressed in scripts/mkvers.sh.
-- The PE Export Tables header contains a timestamp independent from the 
PE header. There is possibly no easy way to fix this without an extra 
tool (or further enhancing peflags).

- usr/lib/lib*.a:
-- Object file time timestamps differ. Could be addressed by adding 'ar' 
option 'D' (deterministic) in Makefiles and scripts/speclib.

- usr/lib/debug/usr/bin/cygwin1.dll.dbg: As expected, because 
cygwin1.dll differ.

If the build-path changes, more files differ (cygcheck.exe, ldd.exe, 
cygserver.exe) because __FILE__ is used and expands to an absolute path 
name.

-- 
Regards,
Christian