Posted to tcl by cgm at Wed May 27 07:56:59 GMT 2026view pretty

More GDB:

(gdb) up
#1  0x00007f79072bab7b in TlsChannelHandlerTimer (clientData=0x555a3ba32590) at ./generic/tlsIO.c:1047
1047        if (Tcl_OutputBuffered(statePtr->self) || BIO_wpending(statePtr->bio)) {

(gdb) p statePtr->self
$3 = (Tcl_Channel) 0x555a3a605240

(gdb) x/4 0x555a3a605240
0x555a3a605240: 0x0     0x2
0x555a3a605250: 0x2     0x1

So 0x555a3a605240 should contain a Channel struct.  The first element of that should be `struct ChannelState *state` but that is null, so when Tcl_OutputBuffered tries to dereference it we get a crash.