happens once in a while. log shows:

[info createHierarchy.cpp:248] Edge: 1,source: 0, target: 3, dist: -342620345
[error createHierarchy.cpp:249] Failed at edges of node 0 of 16

from preprocessing.log:

Preprocessing data for scenario: Time of travel on a winding way
Time: 2012-05-06T12:05:40Z

== OSM data:

<?xml version="1.0" encoding="UTF-8"?>
<osm generator="osrm-test" version="0.6">
  <node id="1" version="1" uid="1" user="osrm" timestamp="2000-00-00T00:00:00Z" lon="1.0" lat="1.0">
    <tag k="name" v="a"/>
  </node>
  <node id="2" version="1" uid="1" user="osrm" timestamp="2000-00-00T00:00:00Z" lon="1.000899199712256" lat="1.0">
    <tag k="name" v="b"/>
  </node>
  <node id="3" version="1" uid="1" user="osrm" timestamp="2000-00-00T00:00:00Z" lon="1.000899199712256" lat="0.999100800287744">
    <tag k="name" v="c"/>
  </node>
  <node id="4" version="1" uid="1" user="osrm" timestamp="2000-00-00T00:00:00Z" lon="1.001798399424512" lat="0.999100800287744">
    <tag k="name" v="d"/>
  </node>
  <node id="5" version="1" uid="1" user="osrm" timestamp="2000-00-00T00:00:00Z" lon="1.0026975991367684" lat="0.999100800287744">
    <tag k="name" v="e"/>
  </node>
  <node id="6" version="1" uid="1" user="osrm" timestamp="2000-00-00T00:00:00Z" lon="1.0044959985612805" lat="0.999100800287744">
    <tag k="name" v="i"/>
  </node>
  <node id="7" version="1" uid="1" user="osrm" timestamp="2000-00-00T00:00:00Z" lon="1.0026975991367684" lat="0.9982016005754878">
    <tag k="name" v="f"/>
  </node>
  <node id="8" version="1" uid="1" user="osrm" timestamp="2000-00-00T00:00:00Z" lon="1.0035967988490244" lat="0.9982016005754878">
    <tag k="name" v="g"/>
  </node>
  <node id="9" version="1" uid="1" user="osrm" timestamp="2000-00-00T00:00:00Z" lon="1.0044959985612805" lat="0.9982016005754878">
    <tag k="name" v="h"/>
  </node>
  <way id="10" version="1" uid="1" user="osrm" timestamp="2000-00-00T00:00:00Z">
    <nd ref="1"/>
    <nd ref="2"/>
    <nd ref="3"/>
    <nd ref="4"/>
    <nd ref="5"/>
    <nd ref="7"/>
    <nd ref="8"/>
    <nd ref="9"/>
    <nd ref="6"/>
    <tag k="highway" v="primary"/>
    <tag k="name" v="abcdefghi"/>
  </way>
</osm>

== Speed profile:
[Scenario: Time of travel on a winding way]
accessTag = bicycle
obeyOneways = yes
obeyBollards = no
useRestrictions = yes
takeMinimumOfSpeeds = yes
defaultSpeed = 15
primary = 15
cycleway = 15
footway = 5

== Extracting cache/6ba7c3f6d8acfbcf95c60d6ef79c66821a699706.osm...
[STXXL-MSG] STXXL v1.3.1 (release)
[STXXL-MSG] 1 disks are allocated, total space: 1 MiB
[info extractor.cpp:86] extracting data from input file cache/6ba7c3f6d8acfbcf95c60d6ef79c66821a699706.osm
[info extractor.cpp:115] Loading speed profiles
[info extractor.cpp:117] Found the following speed profiles:
[0]Scenario: Time of travel on a winding way
[info extractor.cpp:125] Using profile "Scenario: Time of travel on a winding way"
[info extractor.cpp:184] Using 1 GB of RAM for buffers
[warn DataStructures/XMLParser.h:35] Parsing plain .osm/.osm.bz2 is deprecated. Switch to .pbf
[extractor] parsing finished after 0.000585079 seconds
[extractor] Sorting used nodes ... ok, after 0.072063s
[extractor] Erasing duplicate nodes ... ok, after 0.000887156s
[extractor] Sorting all nodes ... ok, after 0.089045s
[extractor] Sorting used ways ... ok, after 0.100168s
[extractor] Sorting restrctns. by from... ok, after 0.100249s
[extractor] Fixing restriction starts ... ok, after 0.100271s
[extractor] Sorting restrctns. by to ... ok, after 2.09808e-05s
[extractor] Fixing restriction ends ... ok, after 1.3113e-05s
[info extractor.cpp:310] usable restrictions: 0
[extractor] Confirming/Writing used nodes ... ok, after 0.00101089s
[extractor] setting number of nodes ... ok
[extractor] Sorting edges by start ... ok, after 0.098141s
[extractor] Setting start coords ... ok, after 0.000669956s
[extractor] Sorting edges by target ... ok, after 0.088068s
[extractor] Setting target coords ... ok, after 0.000540018s
[extractor] setting number of edges ... ok
[extractor] writing street name index ... ok, after 0.000182152s
[info extractor.cpp:498] Processed 11.8061 nodes/sec and 10.4943 edges/sec
[extractor] finished.

== Preparing cache/6ba7c3f6d8acfbcf95c60d6ef79c66821a699706.osm...
[info createHierarchy.cpp:85] Using restrictions from file: cache/6ba7c3f6d8acfbcf95c60d6ef79c66821a699706.osrm.restrictions
[info Util/GraphLoader.h:166] Graph loaded ok and has 8 edges
[info createHierarchy.cpp:113] 0 restrictions, 0 bollard nodes, 0 traffic lights
[info createHierarchy.cpp:125] Generating edge-expanded graph representation
. 10% . 20% . 30% . 40% . 50% . 60% . 70% . 80% . 100%
90% . 100% [info Contractor/EdgeBasedGraphFactory.cpp:306] Sorting edge-based Nodes
[info Contractor/EdgeBasedGraphFactory.cpp:308] Removing duplicate nodes (if any)
[info Contractor/EdgeBasedGraphFactory.cpp:310] Applying vector self-swap trick to free up memory
[info Contractor/EdgeBasedGraphFactory.cpp:312] Node-based graph contains 32 edges
[info Contractor/EdgeBasedGraphFactory.cpp:313] Edge-based graph contains 16 edges, blowup is 0.5
[info Contractor/EdgeBasedGraphFactory.cpp:314] Edge-based graph skipped 0 turns, defined by 0 restrictions.
[info Contractor/EdgeBasedGraphFactory.cpp:315] Generated 16 edge based nodes
[info createHierarchy.cpp:147] writing node map ...
[info createHierarchy.cpp:156] writing info on original edges
[info createHierarchy.cpp:176] building grid ...
[STXXL-MSG] STXXL v1.3.1 (release)
[STXXL-MSG] 1 disks are allocated, total space: 1 MiB
. 10% . 20% . 30% . 40% . 50% . 60% . 70% . 80% . 90% 100%
. 100% [info DataStructures/NNGrid.h:119] sorting grid data consisting of 18 edges...
[info DataStructures/NNGrid.h:122] finished sorting after 0.061718s
writing data .... 10% . 20% . 30% . 40% . 50% . 60% . 70% . 80% . 90% 100%
. 100% sse based
[info createHierarchy.cpp:188] initializing contractor
merged 0 edges out of 32
[info Contractor/Contractor.h:175] Finished building dynamic graph
contractor finished initalization
Contractor is using 1 threads
initializing elimination PQ ...ok
preprocessing .... 10% . 20% . 30% . 40% . 50% . 60% . 70% . 80% [info Contractor/Contractor.h:242] Flushing memory after 13 nodes
. 90% 100%
. 100% [info createHierarchy.cpp:192] Contraction took 0.000311136 sec
[info createHierarchy.cpp:202] Building Node Array
[info createHierarchy.cpp:206] Serializing compacted graph
[info createHierarchy.cpp:248] Edge: 1,source: 0, target: 3, dist: -342620345
[error createHierarchy.cpp:249] Failed at edges of node 0 of 16
*** Exited with code 255.