lots of log errors when slurping Git

Trying jQuery gives me regular intervals of heap space errors, followed by strings of:
...
[java] 15:45:25 ERROR - Missed commit statement C:b147039acc32884b50b955ebd
94eeaa430713786 while in state IN_BODY
[java] 15:45:25 ERROR - Missed commit statement C:b09043fbf6d98adfd22f85a34
7256f545afb2c11 while in state IN_BODY
[java] 15:45:25 ERROR - Missed commit statement C:54035207fe91cb57f49bb8c0c
9f7b4ada8d05346 while in state IN_BODY
...

url:
https://github.com/jquery/jquery.git

I tried the Sammy repo too, which turns out similarly. With a few of these mixed in:
[java] 15:53:27 ERROR - Missed commit statement C:422d921244644d2f293b36198
99435e432baf65a while in state IN_BODY
[java] 15:53:32 WARN - Cannot resolve changeset parent id 0274c2c03347c2f7
6a6c7aa661cb22a30eb9a0b4 for changeset af1acf94c20fed7214f2fd186c135bab7df1b1d2
[java] 15:53:32 WARN - Cannot resolve changeset parent id 61b9c6b21ec2f7e0
0192286529fa16f39ca621da for changeset af1acf94c20fed7214f2fd186c135bab7df1b1d2

But Sammy finishes slurping.
url:
https://github.com/quirkey/sammy.git

If I look around, The file tree is completely empty, but I have changeset data.