First dump:
==========
[...]
(21:10:13) [0xd140b0] [rb_metadata_dbus_load] rb-metadata-dbus-service.c:126: loading metadata from file:///file1.xm
(21:10:13) [0xd140b0] [rb_metadata_load] rb-metadata-gst.c:732: loading metadata for uri: file:///file1.xm
(21:10:13) [0xd140b0] [rb_metadata_load] rb-metadata-gst.c:780: going to PAUSED for metadata, uri: file:///file1.xm
(21:10:13) [0xd140b0] [rb_metadata_gst_new_decoded_pad_cb] rb-metadata-gst.c:523: got decoded audio pad of type audio/x-raw-int
(21:10:13) [0xd140b0] [rb_metadata_gst_typefind_cb] rb-metadata-gst.c:489: found type audio/x-mod
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from fakesink
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from fakesink
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from typefind
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from decodebin
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from urisrc
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from pipeline
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from modplug0
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type stream-status from sink
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from modplug0
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from typefind
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type stream-status from sink
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from urisrc
*** glibc detected *** /usr/libexec/rhythmbox-metadata: realloc(): invalid next size: 0x00007f1d48051680 ***
(21:10:13) [0xd140b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from fakesink
(21:10:23) [0x1de3040] [rhythmdb_save] rhythmdb.c:3332: saving the rhythmdb and blocking
(21:10:23) [0x1de3040] [rhythmdb_save_async] rhythmdb.c:3314: saving the rhythmdb in the background
(21:10:23) [0x1de3040] [rhythmdb_read_enter] rhythmdb.c:1253: counter: 1
(21:10:23) [0x2ef3ab0] [rhythmdb_save_thread_main] rhythmdb.c:3262: entering save thread
(21:10:23) [0x2ef3ab0] [rhythmdb_save_thread_main] rhythmdb.c:3270: no save needed, ignoring
(21:10:23) [0x1de3040] [rhythmdb_save] rhythmdb.c:3349: done
(21:10:23) [0x1de3040] [rhythmdb_process_one_event] rhythmdb.c:2660: processing RHYTHMDB_EVENT_DB_SAVED
(21:10:23) [0x1de3040] [rhythmdb_read_leave] rhythmdb.c:1267: counter: 0
(21:10:23) [0x1de3040] [rhythmdb_process_one_event] rhythmdb.c:2657: processing RHYTHMDB_EVENT_THREAD_EXITED
(21:10:25) [0x1de3040] [rb_audioscrobbler_should_handshake] rb-audioscrobbler.c:740: No username set
(21:10:28) [0x28da9d0] [kill_metadata_service] rb-metadata-dbus-client.c:151: closing dbus connection
(21:10:28) [0x28da9d0] [kill_metadata_service] rb-metadata-dbus-client.c:161: killing child process
(21:10:28) [0x28da9d0] [kill_metadata_service] rb-metadata-dbus-client.c:168: closing metadata child process stdout pipe
(21:10:28) [0x1de3040] [rhythmdb_process_one_event] rhythmdb.c:2635: processing RHYTHMDB_EVENT_METADATA_LOAD
(21:10:28) [0x1de3040] [rhythmdb_add_import_error_entry] rhythmdb.c:2229: adding import error for file:///file1.xm: Internal GStreamer problem; file a bug
[...]

2nd dump:
========
[...]
(21:23:19) [0x10240b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type stream-status from sink
(21:23:19) [0x10240b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from urisrc
(21:23:19) [0x10240b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from fakesink
(21:23:19) [0x10240b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from decodebin
(21:23:19) [0x10240b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from fakesink
(21:23:19) [0x10240b0] [rb_metadata_bus_handler] rb-metadata-gst.c:676: message of type state-changed from fakesink
(21:23:19) [0x10240b0] [rb_metadata_gst_load_tag] rb-metadata-gst.c:444: processed string tag "title": "heaven_mooncell"
(21:23:19) [0x10240b0] [rb_metadata_gst_load_tag] rb-metadata-gst.c:388: no metadata field for tag "beats-per-minute"
*** glibc detected *** /usr/libexec/rhythmbox-metadata: malloc(): memory corruption: 0x00007f903c004160 ***
(21:23:24) [0x10240b0] [rb_metadata_load] rb-metadata-gst.c:805: failed to go to PAUSED for file:///file2.XM
[...]

(source code of rb-metadata-gst.c could be found here: http://rhythmbox.sourcearchive.com/documentation/0.12.8/rb-metadata-gst_8c-source.html)
