From 6e2e984af0a2f3197ff9ca6897a11fabdeb67ea7 Mon Sep 17 00:00:00 2001
From: Mikael Voss <mvs@nyantec.com>
Date: Mon, 3 Mar 2025 17:19:00 +0100
Subject: [PATCH] lib/path: allow CA paths in hasStorePathPrefix

---
 lib/path/default.nix    |  8 +++++++-
 lib/path/tests/unit.nix | 10 ++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/lib/path/default.nix b/lib/path/default.nix
index 4ffee65e1cf5..be559eadf182 100644
--- a/lib/path/default.nix
+++ b/lib/path/default.nix
@@ -159,7 +159,13 @@ let
     # but this is not fully specified, so let's tie this too much to the currently implemented concept of store paths.
     # Similar reasoning applies to the validity of the name part.
     # We care more about discerning store path-ness on realistic values. Making it airtight would be fragile and slow.
-    && match ".{32}-.+" (elemAt components storeDirLength) != null;
+    && match ".{32}-.+" (elemAt components storeDirLength) != null
+    # alternatively match content‐addressed derivations, which _currently_ do
+    # not have a store directory prefix.
+    # This is a workaround for https://github.com/NixOS/nix/issues/12361 which
+    # was needed during the experimental phase of ca-derivations and should be
+    # removed once the issue has been resolved.
+    || match "[0-9a-z]{52}" (head components) != null;
 
 in
 # No rec! Add dependencies on this file at the top.
diff --git a/lib/path/tests/unit.nix b/lib/path/tests/unit.nix
index 903e8ff0acff..a52b4f44e51d 100644
--- a/lib/path/tests/unit.nix
+++ b/lib/path/tests/unit.nix
@@ -137,6 +137,16 @@ let
       expected = true;
     };
 
+    # Test paths for content‐addressed derivations
+    testHasStorePathPrefixExample7 = {
+      expr = hasStorePathPrefix (/. + "/1121rp0gvr1qya7hvy925g5kjwg66acz6sn1ra1hca09f1z5dsab");
+      expected = true;
+    };
+    testHasStorePathPrefixExample8 = {
+      expr = hasStorePathPrefix (/. + "/1121rp0gvr1qya7hvy925g5kjwg66acz6sn1ra1hca09f1z5dsab/foo/bar");
+      expected = true;
+    };
+
     # Test examples from the lib.path.subpath.isValid documentation
     testSubpathIsValidExample1 = {
       expr = subpath.isValid null;