python: fix slow startup time

Closes #315
2021-08-10 16:00:58 +00:00 · 2021-08-10 16:00:58 +00:00 · 42f4937f70
commit 42f4937f70
parent a95ba8739b
1 changed files with 9 additions and 0 deletions
--- a/extra/python/build
+++ b/extra/python/build
@ -1,5 +1,14 @@
 #!/bin/sh -e

+# Without this environment variable being set to some arbitrary value,
+# python's module loader uses timestamps for cache invalidation. Something
+# goes wrong here and all pyc files are seen as stale.
+#
+# By setting this value, python uses checksums for cache invalidation which
+# (on my machine) drops startup time from 3 seconds to 0.060s. Further
+# investigation is needed.
+export SOURCE_DATE_EPOCH=1628593994
+
 # Remove util-linux dependency among other things.
 cat >> Modules/Setup <<EOF
 *disabled*