From 11e47e7dfbca2f330b693665a4ee38302d1f6ad2 Mon Sep 17 00:00:00 2001
From: Artturin <Artturin@artturin.com>
Date: Thu, 14 Sep 2023 04:36:25 +0300
Subject: [PATCH] factor out doBind from runChild

---
 src/libstore/build/local-derivation-goal.cc | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/libstore/build/local-derivation-goal.cc b/src/libstore/build/local-derivation-goal.cc
index 204acab11..9592df43a 100644
--- a/src/libstore/build/local-derivation-goal.cc
+++ b/src/libstore/build/local-derivation-goal.cc
@@ -386,6 +386,26 @@ void LocalDerivationGoal::cleanupPostOutputsRegisteredModeNonCheck()
     cleanupPostOutputsRegisteredModeCheck();
 }
 
+#if __linux__
+static void doBind(const Path & source, const Path & target, bool optional = false) {
+    debug("bind mounting '%1%' to '%2%'", source, target);
+    struct stat st;
+    if (stat(source.c_str(), &st) == -1) {
+        if (optional && errno == ENOENT)
+            return;
+        else
+            throw SysError("getting attributes of path '%1%'", source);
+    }
+    if (S_ISDIR(st.st_mode))
+        createDirs(target);
+    else {
+        createDirs(dirOf(target));
+        writeFile(target, "");
+    }
+    if (mount(source.c_str(), target.c_str(), "", MS_BIND | MS_REC, 0) == -1)
+        throw SysError("bind mount from '%1%' to '%2%' failed", source, target);
+};
+#endif
 
 void LocalDerivationGoal::startBuilder()
 {