From 5b4bb8cd8af4af8e8da9adeefe0351c2e628678a Mon Sep 17 00:00:00 2001
From: Puck Meerburg <puck@puckipedia.com>
Date: Thu, 1 May 2025 13:20:05 +0000
Subject: [PATCH] (zilch nix drv): fix serialized derivation format caching

This was broken at some point, and I'm not sure if this is a load-bearing
bug. Let's find out.
---
 core/src/nix/drv.sld | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/core/src/nix/drv.sld b/core/src/nix/drv.sld
index c5da1cf..195fb45 100644
--- a/core/src/nix/drv.sld
+++ b/core/src/nix/drv.sld
@@ -71,10 +71,11 @@
       (serialized derivation-cached-data-serialized set-derivation-cached-data-serialized!))
 
     (define-record-printer (<derivation-cached-data> drv out)
-      (fprintf out "#<derivation-cached-data path: ~S, hash: ~S, deferred: ~S>"
+      (fprintf out "#<derivation-cached-data path: ~S, hash: ~S, deferred: ~S (has serialized? ~S)>"
         (derivation-cached-data-path drv)
         (derivation-cached-data-modulo-hash drv)
-        (derivation-cached-data-is-deferred drv)))
+        (derivation-cached-data-is-deferred drv)
+        (not (not (derivation-cached-data-serialized drv)))))
      
     ;; An entire derivation.
     ;; `outputs` is stored as an alist of output name to `<derivation-output>` object.
@@ -498,14 +499,14 @@
     (define derivation-serialize
       (case-lambda
         ((drv) (derivation-serialize drv (current-output-port)))
-        ((drv port) (derivation-serialize drv port (derivation-input-drvs drv)))
+        ((drv port)
+         (if (derivation-cached-data-serialized (derivation-cached-data drv))
+             (write-bytevector (derivation-cached-data-serialized (derivation-cached-data drv)) port)
+             (call-with-port (open-output-bytevector)
+               (lambda (nport)
+                 (derivation-serialize-internal drv nport (derivation-input-drvs drv))
+                 (set-derivation-cached-data-serialized! (derivation-cached-data drv) (get-output-bytevector nport))
+                 (write-bytevector (get-output-bytevector nport) port)))))
         ((drv port masked)
-         (if masked (derivation-serialize-internal drv port masked)
-           (if (derivation-cached-data-serialized (derivation-cached-data drv))
-               (write-bytevector (derivation-cached-data-serialized (derivation-cached-data drv)) port)
-               (call-with-port (open-output-bytevector)
-                 (lambda (nport)
-                   (derivation-serialize-internal drv nport #f)
-                   (set-derivation-cached-data-serialized! (derivation-cached-data drv) (get-output-bytevector nport))
-                   (write-bytevector (get-output-bytevector nport) port))))))))))
+         (derivation-serialize-internal drv port masked))))))