Always provide the same date and time in 'Py_GetBuildInfo'.
This is the information shown at the REPL and in 'sys.version'.
We cannot pass it in CPPFLAGS due to whitespace in the DATE string.

--- a/Modules/getbuildinfo.c
+++ b/Modules/getbuildinfo.c
@@ -4,6 +4,10 @@
 #include <stdio.h>
 #endif
 
+/* Deterministic date and time.  */
+#define DATE "Jan  1 1970"
+#define TIME "00:00:01"
+
 #ifndef DATE
 #ifdef __DATE__
 #define DATE __DATE__
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<div class='path'>path: <a href='/guix/log/?id=ec0a2444176bef974809c15ad4c6acb7f5423ac1'>root</a>/<a href='/guix/log/etc?id=ec0a2444176bef974809c15ad4c6acb7f5423ac1'>etc</a>/<a href='/guix/log/etc/gnu-store.mount.in?id=ec0a2444176bef974809c15ad4c6acb7f5423ac1'>gnu-store.mount.in</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/etc/gnu-store.mount.in?id=ec0a2444176bef974809c15ad4c6acb7f5423ac1&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-05-17 15:16:52 +0200'>2020-05-17</span></td><td><a href='/guix/commit/etc/gnu-store.mount.in?id=301572aa87a9587465277d48325dd88fcbf1b312'>etc: Add a systemd unit to bind-mount @storedir@ read-only.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/gnu-store.mount.in: New file.
* nix/local.mk (nodist_systemdservice_DATA): Add it.
(etc/%.mount): New rule for it.
* etc/guix-install.sh (sys_enable_guix_daemon): Install it.
* doc/guix.texi (Binary Installation): Document it.
* .gitignore: Ignore changes to it.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>