[GRASS-dev] [GRASS GIS] #3042: Patches to make the build reproducible (fileordering, randomness)

[GRASS GIS]

#3042: Patches to make the build reproducible (fileordering, randomness)
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  Reporter:  sebastic     |      Owner:  grass-dev@…
      Type:  defect       |     Status:  new
  Priority:  critical     |  Milestone:  7.0.5
 Component:  Compiling    |    Version:  7.0.4
Resolution:               |   Keywords:
       CPU:  Unspecified  |   Platform:  Linux
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Comment (by glynn):

 Replying to [ticket:3042 sebastic]:

 > 2) Randomness issue: html/colortables/random.png is built using a
 pseudo-random generator seeded with build-time value. See patch `04
 -srand48_auto-from-SOURCE_DATE_EPOCH.patch` that uses the [https
 ://reproducible-builds.org/specs/source-date-epoch/ SOURCE_DATE_EPOCH]
 environment variable (when set) to set a seed from last `debian/changelog`
 entry date.

 While I agree with the idea, G_srand48_auto() shouldn't be using this
 variable directly, but something more appropriate, e.g. GRASS_RANDOM_SEED
 (or GRASS_RND_SEED, which is what r.mapcalc used prior to the RNG
 changes).

 Debian can then set that variable from $SOURCE_DATE_EPOCH as part of their
 build process.

 In theory, modules which use randomness should be providing a command-line
 option to get the seed, with G_srand48_auto() only being used if the user
 specifically wants a non-deterministic seed. But that probably isn't going
 to happen in the foreseeable future.

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3042#comment:3>
GRASS GIS <https://grass.osgeo.org>