From 7adb10d29b0041a93d1afeec197bf9af6e8b25b5 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Fri, 31 May 2019 20:12:59 +0200
Subject: [PATCH] Fix reading the lockfile of a flake in a subdirectory

---
 src/libexpr/primops/flake.cc | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/libexpr/primops/flake.cc b/src/libexpr/primops/flake.cc
index af7d51834..235e10922 100644
--- a/src/libexpr/primops/flake.cc
+++ b/src/libexpr/primops/flake.cc
@@ -482,9 +482,12 @@ ResolvedFlake resolveFlake(EvalState & state, const FlakeRef & topRef, HandleLoc
     Flake flake = getFlake(state, topRef, allowedToUseRegistries(handleLockFile, true));
     LockFile oldLockFile;
 
-    if (!recreateLockFile (handleLockFile)) {
+    if (!recreateLockFile(handleLockFile)) {
         // If recreateLockFile, start with an empty lockfile
-        oldLockFile = readLockFile(flake.sourceInfo.storePath + "/flake.lock"); // FIXME: symlink attack
+        // FIXME: symlink attack
+        oldLockFile = readLockFile(
+            state.store->toRealPath(flake.sourceInfo.storePath)
+            + "/" + flake.sourceInfo.resolvedRef.subdir + "/flake.lock");
     }
 
     LockFile lockFile(oldLockFile);