Hi all. Some people at freenode found out that function read-char-no-hang blocks on SB-SYS:WAIT-UNTIL-FD-USABLE. Here is a backtrace: http://paste.lisp.org/display/94690 I wrote simple test case to reproduce this issue, it can be found at: http://paste.lisp.org/display/94692#2 SBCL 1.0.30, x86-64 Good luck -- gzip4