Honor the 'SOURCE_DATE_EPOCH' environment variable to allow for
determinitic builds.

--- a/Lib/py_compile.py
+++ b/Lib/py_compile.py
@@ -105,7 +105,10 @@ def compile(file, cfile=None, dfile=None, doraise=False):
     """
     with open(file, 'U') as f:
         try:
-            timestamp = long(os.fstat(f.fileno()).st_mtime)
+            if 'SOURCE_DATE_EPOCH' in os.environ:
+                timestamp = long(os.environ['SOURCE_DATE_EPOCH'])
+            else:
+                timestamp = long(os.fstat(f.fileno()).st_mtime)
         except AttributeError:
             timestamp = long(os.stat(file).st_mtime)
         codestring = f.read()
diff --git a/Python/import.c b/Python/import.c
index e47ce63..7eecf9c 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -945,6 +945,11 @@ write_compiled_module(PyCodeObject *co, char *cpathname, struct stat *srcstat, t
     /* Now write the true mtime (as a 32-bit field) */
     fseek(fp, 4L, 0);
     assert(mtime <= 0xFFFFFFFF);
+    if (Py_GETENV("SOURCE_DATE_EPOCH") != NULL) {
+	const char *epoch = Py_GETENV("SOURCE_DATE_EPOCH");
+	mtime = atoi(epoch);
+    }
+
     PyMarshal_WriteLongToFile((long)mtime, fp, Py_MARSHAL_VERSION);
     fflush(fp);
     fclose(fp);
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<tr><td><span title='2024-04-13 23:06:57 +0100'>2024-04-13</span></td><td><a href='/guix/commit/gnu/packages/data-language.scm?id=ef9a2f9e91d37c0d93e689eb26ebeb6483655968'>gnu: Add gnudatalanguage.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/data-language.scm: New file.
* gnu/packages/data-language.scm (gnudatalanguage): New variable.
* gnu/local.mk: Add gnu/packages/data-language.scm to scope.

Signed-off-by: Sharlatan Hellseher &lt;sharlatanus@gmail.com&gt;
Change-Id: Icf830df85ed8e6f067344af96dbb7d202e677dee
</span></span></td><td>Antero Mejr</td></tr>