From 446b827baedde7ba3ca44f9ef51940e28e13fb87 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Mon, 26 Mar 2012 23:18:36 +0200
Subject: [PATCH] Mac OS X fix

---
 src/libstore/gc.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc
index 56cb97d87..a21ccc9d2 100644
--- a/src/libstore/gc.cc
+++ b/src/libstore/gc.cc
@@ -532,6 +532,9 @@ bool LocalStore::tryToDelete(GCState & state, const Path & path)
                 state.bytesInvalidated += queryPathInfo(path).narSize;
                 invalidatePathChecked(path);
                 makeMutable(path.c_str());
+                // Mac OS X cannot rename directories if they are read-only.
+                if (chmod(path.c_str(), st.st_mode | S_IWUSR) == -1)
+                    throw SysError(format("making `%1%' writable") % path);
                 Path tmp = (format("%1%-gc-%2%") % path % getpid()).str();
                 if (rename(path.c_str(), tmp.c_str()))
                     throw SysError(format("unable to rename `%1%' to `%2%'") % path % tmp);