diff -crB guix-master/nix/libstore/build.cc guix-userspace/nix/libstore/build.cc
*** guix-master/nix/libstore/build.cc	Wed May  4 09:56:21 2016
--- guix-userspace/nix/libstore/build.cc	Mon Apr 25 16:39:29 2016
***************
*** 1811,1818 ****
          buildUser.kill();
  
          /* Change ownership of the temporary build directory. */
!         if (chown(tmpDir.c_str(), buildUser.getUID(), buildUser.getGID()) == -1)
!             throw SysError(format("cannot change ownership of '%1%'") % tmpDir);
      }
  
      if (useChroot) {
--- 1811,1818 ----
          buildUser.kill();
  
          /* Change ownership of the temporary build directory. */
!         //if (chown(tmpDir.c_str(), buildUser.getUID(), buildUser.getGID()) == -1)
!         //    throw SysError(format("cannot change ownership of '%1%'") % tmpDir);
      }
  
      if (useChroot) {
***************
*** 1832,1839 ****
          if (mkdir(chrootRootDir.c_str(), 0750) == -1)
              throw SysError(format("cannot create ‘%1%’") % chrootRootDir);
  
!         if (chown(chrootRootDir.c_str(), 0, buildUser.getGID()) == -1)
!             throw SysError(format("cannot change ownership of ‘%1%’") % chrootRootDir);
  
          /* Create a writable /tmp in the chroot.  Many builders need
             this.  (Of course they should really respect $TMPDIR
--- 1832,1839 ----
          if (mkdir(chrootRootDir.c_str(), 0750) == -1)
              throw SysError(format("cannot create ‘%1%’") % chrootRootDir);
  
!         //if (chown(chrootRootDir.c_str(), 0, buildUser.getGID()) == -1)
!         //    throw SysError(format("cannot change ownership of ‘%1%’") % chrootRootDir);
  
          /* Create a writable /tmp in the chroot.  Many builders need
             this.  (Of course they should really respect $TMPDIR
***************
*** 1889,1896 ****
          createDirs(chrootStoreDir);
          chmod_(chrootStoreDir, 01775);
  
!         if (chown(chrootStoreDir.c_str(), 0, buildUser.getGID()) == -1)
!             throw SysError(format("cannot change ownership of ‘%1%’") % chrootStoreDir);
  
          foreach (PathSet::iterator, i, inputPaths) {
              struct stat st;
--- 1889,1896 ----
          createDirs(chrootStoreDir);
          chmod_(chrootStoreDir, 01775);
  
!         //if (chown(chrootStoreDir.c_str(), 0, buildUser.getGID()) == -1)
!         //    throw SysError(format("cannot change ownership of ‘%1%’") % chrootStoreDir);
  
          foreach (PathSet::iterator, i, inputPaths) {
              struct stat st;
***************
*** 1999,2010 ****
--- 1999,2014 ----
      */
  #if CHROOT_ENABLED
      if (useChroot) {
+         pid = fork();
+         if (pid == 0) runChild();
+ 	/*
  	char stack[32 * 1024];
  	int flags = CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | CLONE_NEWUTS | SIGCHLD;
  	if (!fixedOutput) flags |= CLONE_NEWNET;
  	pid = clone(childEntry, stack + sizeof(stack) - 8, flags, this);
  	if (pid == -1)
  	    throw SysError("cloning builder process");
+ 	*/
      } else
  #endif
      {
***************
*** 2045,2051 ****
  
          commonChildInit(builderOut);
  
! #if CHROOT_ENABLED
          if (useChroot) {
              /* Initialise the loopback interface. */
              AutoCloseFD fd(socket(PF_INET, SOCK_DGRAM, IPPROTO_IP));
--- 2049,2055 ----
  
          commonChildInit(builderOut);
  
! #if CHROOT_ENABLED && 0
          if (useChroot) {
              /* Initialise the loopback interface. */
              AutoCloseFD fd(socket(PF_INET, SOCK_DGRAM, IPPROTO_IP));