[PATCH] GPGME: remove BUILD_TIMESTAMP

[Daniel Kahn Gillmor]

embedding the timestamp of the configuration into the build makes the
binary output unreproducible, which makes it more difficult to verify
that any particular set of binaries is build from the expected source
code.

This changeset removes all attempts at embedding the build timestamp
in GPGME.  We already have PACKAGE_VERSION (and BUILD_REVISION when
building from git) as identifiers of what was built, so we should be
able to let go of this source of variation in the build without much
of a drawback.

If removal of BUILD_TIMESTAMP isn't acceptable for gpgme, we should
allow it to be externally set for people who are trying to rebuild the
package reproducibly.

See also:
https://wiki.debian.org/ReproducibleBuilds/Howto#Files_in_data.tar_contain_timestamps

Signed-off-by: Daniel Kahn Gillmor <dkg at fifthhorseman.net>
---
 configure.ac          | 5 -----
 src/version.c         | 2 +-
 src/versioninfo.rc.in | 1 -
 3 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/configure.ac b/configure.ac
index be36a42..66feec8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -260,11 +260,6 @@ changequote([,])dnl
 BUILD_FILEVERSION="${BUILD_FILEVERSION}mym4_revision_dec"
 AC_SUBST(BUILD_FILEVERSION)
 
-BUILD_TIMESTAMP=`date -u +%Y-%m-%dT%H:%M+0000 2>/dev/null || date`
-AC_SUBST(BUILD_TIMESTAMP)
-AC_DEFINE_UNQUOTED(BUILD_TIMESTAMP, "$BUILD_TIMESTAMP",
-                   [The time this package was configured for a build])
-
 #
 # Options to disable some regression tests
 #
diff --git a/src/version.c b/src/version.c
index 15e5aee..09602b0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -92,7 +92,7 @@ cright_blurb (void)
     "This is GPGME " PACKAGE_VERSION " - The GnuPG Made Easy library\n"
     CRIGHTBLURB
     "\n"
-    "(" BUILD_REVISION " " BUILD_TIMESTAMP ")\n"
+    "(" BUILD_REVISION ")\n"
     "\n\n";
   return blurb;
 }
diff --git a/src/versioninfo.rc.in b/src/versioninfo.rc.in
index a4ab0af..50df4fd 100644
--- a/src/versioninfo.rc.in
+++ b/src/versioninfo.rc.in
@@ -45,7 +45,6 @@ BEGIN
             VALUE "PrivateBuild", "\0"
             VALUE "ProductName", "GPGME\0"
             VALUE "ProductVersion", "@VERSION@\0"
-            VALUE "SpecialBuild", "@BUILD_TIMESTAMP@\0"
         END
     END
 END
-- 
2.1.4