A test/format job failed. The error message was:

[1427331610:422856][106683:0x7f6cca7fc700], t, file:wt.wt, eviction-worker: key 4 on page at [write-check] has a prefix compression count of 97, larger than the length of the previous key, 24
[1427331610:423327][106683:0x7f6cca7fc700], t, eviction-worker: cache eviction worker error: WT_ERROR: non-specific WiredTiger error
[1427331610:423335][106683:0x7f6cca7fc700], t, eviction-worker: the process must exit and restart: WT_PANIC: WiredTiger library panic
[1427331610:423339][106683:0x7f6cca7fc700], t, eviction-worker: aborting WiredTiger library
t: next: WT_PANIC: WiredTiger library panic

The process was hung at the end - it seems as though multiple threads raced to

 in test/format.

The test/format configuration was:

############################################

1. 1. 1. 1. RUN PARAMETERS
            ############################################
            abort=0
            auto_throttle=1
            firstfit=0
            bitcnt=1
            bloom=1
            bloom_bit_count=43
            bloom_hash_count=16
            bloom_oldest=0
            cache=99
            checkpoints=1
            checksum=uncompressed
            chunk_size=3
            compaction=0
            compression=bzip
            data_extend=0
            data_source=table
            delete_pct=29
            dictionary=0
            evict_max=5
            file_type=row-store
            backups=0
            huffman_key=0
            huffman_value=0
            insert_pct=10
            internal_key_truncation=1
            internal_page_max=9
            isolation=random
            key_gap=14
            key_max=256
            key_min=256
            leak_memory=0
            leaf_page_max=9
            logging=0
            logging_archive=1
            logging_prealloc=0
            lsm_worker_threads=4
            merge_max=19
            mmap=1
            ops=100000
            prefix_compression=1
            prefix_compression_min=4
            repeat_data_pct=0
            reverse=0
            rows=100000
            runs=1
            split_pct=54
            statistics=0
            statistics_server=0
            threads=7
            timer=20
            value_max=1889
            value_min=10
            wiredtiger_config=
            write_pct=34
            ############################################

A link to the failure: http://build.wiredtiger.com:8080/job/wiredtiger-test-format-stress/6457/console