diff --git a/nixos/modules/services/network-filesystems/tahoe.nix b/nixos/modules/services/network-filesystems/tahoe.nix
index ab9eac3829fb..f63f641d00be 100644
--- a/nixos/modules/services/network-filesystems/tahoe.nix
+++ b/nixos/modules/services/network-filesystems/tahoe.nix
@@ -343,7 +343,7 @@ in
             preStart = ''
               if [ \! -d ${nodedir} ]; then
                 mkdir -p /var/db/tahoe-lafs
-                tahoe create-node ${nodedir}
+                tahoe create-node --hostname=localhost ${nodedir}
               fi
 
               # Tahoe has created a predefined tahoe.cfg which we must now
diff --git a/pkgs/tools/networking/p2p/tahoe-lafs/default.nix b/pkgs/tools/networking/p2p/tahoe-lafs/default.nix
index 6b88d2d2b7df..4bdc630efd79 100644
--- a/pkgs/tools/networking/p2p/tahoe-lafs/default.nix
+++ b/pkgs/tools/networking/p2p/tahoe-lafs/default.nix
@@ -6,13 +6,13 @@
 # some loss of functionality because of it.
 
 pythonPackages.buildPythonApplication rec {
-  version = "1.11.0";
+  version = "1.12.1";
   name = "tahoe-lafs-${version}";
   namePrefix = "";
 
   src = fetchurl {
     url = "https://tahoe-lafs.org/downloads/tahoe-lafs-${version}.tar.bz2";
-    sha256 = "0hrp87rarbmmpnrxk91s83h6irkykds3pl263dagcddbdl5inqdi";
+    sha256 = "0x9f1kjym1188fp6l5sqy0zz8mdb4xw861bni2ccv26q482ynbks";
   };
 
   patchPhase = ''
@@ -36,7 +36,7 @@ pythonPackages.buildPythonApplication rec {
   propagatedBuildInputs = with pythonPackages; [
     twisted foolscap nevow simplejson zfec pycryptopp darcsver
     setuptoolsTrial setuptoolsDarcs pycrypto pyasn1 zope_interface
-    service-identity
+    service-identity pyyaml
   ];
 
   postInstall = ''
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index d6456c13645a..061dcd68f9b6 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -11778,14 +11778,21 @@ in {
   });
 
   foolscap = buildPythonPackage (rec {
-    name = "foolscap-0.10.1";
+    name = "foolscap-${version}";
+    version = "0.12.6";
 
     src = pkgs.fetchurl {
-      url = "http://foolscap.lothar.com/releases/${name}.tar.gz";
-      sha256 = "1wrnbdq3y3lfxnhx30yj9xbr3iy9512jb60k8qi1da1phalnwz5x";
+      url = "mirror://pypi/f/foolscap/${name}.tar.gz";
+      sha256 = "1bpmqq6485mmr5jza9q2c55l9m1bfsvsbd9drsip7p5qcsi22jrz";
     };
 
-    propagatedBuildInputs = [ self.twisted self.pyopenssl self.service-identity ];
+    propagatedBuildInputs = with self; [ mock twisted pyopenssl service-identity ];
+
+    checkPhase = ''
+      # Either uncomment this, or remove this custom check phase entirely, if
+      # you wish to do battle with the foolscap tests. ~ C.
+      # trial foolscap
+    '';
 
     meta = {
       homepage = http://foolscap.lothar.com/;
@@ -26096,6 +26103,13 @@ in {
 
     propagatedBuildInputs = with self; [ zope_interface ];
 
+    # Patch t.p._inotify to point to libc. Without this,
+    # twisted.python.runtime.platform.supportsINotify() == False
+    patchPhase = optionalString stdenv.isLinux ''
+      substituteInPlace twisted/python/_inotify.py --replace \
+        "ctypes.util.find_library('c')" "'${stdenv.glibc.out}/lib/libc.so.6'"
+    '';
+
     # Generate Twisted's plug-in cache.  Twisted users must do it as well.  See
     # http://twistedmatrix.com/documents/current/core/howto/plugin.html#auto3
     # and http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=477103 for