Changelog nore for #1238 and add --help description.

- Merge #1238: Prefer SOURCE_DATE_EPOCH over actual time.
  Add --help output description for the SOURCE_DATE_EPOCH variable.

configure

@@ -712,6 +712,7 @@ SSLLIB
 HAVE_SSL
 PC_CRYPTO_DEPENDENCY
 CONFIG_DATE
+SOURCE_DATE_EPOCH
 GCC_DOCKER_LINTFLAGS
 NETBSD_LINTFLAGS
 PYUNBOUND_UNINSTALL
@@ -959,6 +960,7 @@ SYSTEMD_LIBS
 SYSTEMD_DAEMON_CFLAGS
 SYSTEMD_DAEMON_LIBS
 PYTHON_VERSION
+SOURCE_DATE_EPOCH
 PROTOBUFC_CFLAGS
 PROTOBUFC_LIBS'
 
@@ -1752,6 +1754,10 @@ Some influential environment variables:
               The installed Python version to use, for example '2.3'. This
               string will be appended to the Python interpreter canonical
               name.
+  SOURCE_DATE_EPOCH
+              If it is set, it uses the value of that variable instead of the
+              current time as the build timestamp. The format is a unix
+              timestamp. This enables reproducible build output.
   PROTOBUFC_CFLAGS
               C compiler flags for PROTOBUFC, overriding pkg-config
   PROTOBUFC_LIBS
@@ -19915,6 +19921,7 @@ printf "%s\n" "$CONFIG_DATE" >&6; }
 
 
 
+
 # Checks for libraries.
 
 # libnss

configure.ac

@@ -910,6 +910,7 @@ if test "`uname`" = "Linux"; then
 	AC_SUBST(GCC_DOCKER_LINTFLAGS)
 fi
 AX_BUILD_DATE_EPOCH(CONFIG_DATE, [%Y%m%d])
+AC_ARG_VAR(SOURCE_DATE_EPOCH, [If it is set, it uses the value of that variable instead of the current time as the build timestamp. The format is a unix timestamp. This enables reproducible build output.])
 AC_SUBST(CONFIG_DATE)
 
 # Checks for libraries.

doc/Changelog

@@ -1,3 +1,7 @@
+28 February 2025: Wouter
+	- Merge #1238: Prefer SOURCE_DATE_EPOCH over actual time.
+	  Add --help output description for the SOURCE_DATE_EPOCH variable.
+
 25 February 2025: Wouter
 	- Merge #1243: Do not shadow tm on line 236.