Transmission broken with -current?

[Scott Ellis <scotte%warped.com@localhost>]

I upgraded from a May 2nd amd64/-current to one as of June 14th, and am 
experiencing weird breakage with "Transmission".  When an RPC is used 
(e.g., transmission-remote against transmission-daemon) I get a bus 
error.  Backtrace shows:
#0  0x000000000045a800 in evbuffer_add_printf ()
#1  0x000000000040a22e in jsonRealFunc (val=0x7f7ffc790ce0,
    vdata=0x7f7ffbfff9c8) at bencode.c:1304
#2  0x0000000000409aaf in bencWalk (top=0x7f7ffbfffa18, walkFuncs=0x48edc0,
    user_data=0x7f7ffbfff9c8) at bencode.c:1035
#3  0x000000000040a974 in tr_bencToBuf (top=0x7f7ffbfffa18,
    mode=TR_FMT_JSON_LEAN, buf=0x7f7ffc70a2c0) at bencode.c:1512
#4  0x000000000044edc7 in request_exec (session=0x7f7ffc908180,
    request=0x7f7ffbfffb08, callback=0x43f323 <rpc_response_func>,
    callback_user_data=0x7f7ffc708160) at rpcimpl.c:1364
#5  0x000000000044ef91 in tr_rpc_request_exec_json (session=0x7f7ffc908180,
    request_json=0x7f7ffc781200, request_len=47,
    callback=0x43f323 <rpc_response_func>, 
callback_user_data=0x7f7ffc708160)
    at rpcimpl.c:1401
#6  0x000000000043f47a in handle_rpc (req=0x7f7ffc79d080,
    server=0x7f7ffc7030c0) at rpc-server.c:521
#7  0x000000000043f952 in handle_request (req=0x7f7ffc79d080,
    arg=0x7f7ffc7030c0) at rpc-server.c:641
#8  0x000000000045e0f7 in evhttp_read_body ()
#9  0x000000000045e545 in evhttp_read ()
#10 0x00000000004599eb in event_base_loop ()
#11 0x0000000000420e19 in libeventThreadFunc (veh=0x7f7ffc910090)
    at trevent.c:238

If there is "resume" data present, the crash is in tr_snprintf() .
Reverting to an old libc.so and libcrypto.so (reverting == 
LD_LIBRARY_PATH'ing so that transmission-daemon picks those up) does not 
help.  These are the relevant libraries that changed during May 
2nd->Jule 14th.  This leads me to suspect some kernel change.

Ideas?