I had a crash with NS, current CVS version. I showed the font panel, searched for "Lucida" in it, and then clicked on one of the Lucida fonts. I can't reproduce the crash, but the trace is below. Process: Emacs [31194] Path: /Users/dr/Projects/Bazaar-Playground/emacs.cvs/ nextstep/Emacs.app/Contents/MacOS/Emacs Identifier: org.gnu.Emacs Version: Version 23.0.90 (9.0) Code Type: X86 (Native) Parent Process: launchd [76] Date/Time: 2009-03-01 16:07:04.692 -0500 OS Version: Mac OS X 10.5.6 (9G55) Report Version: 6 Exception Type: EXC_BREAKPOINT (SIGABRT) Exception Codes: 0x0000000000000002, 0x0000000000000000 Crashed Thread: 0 Application Specific Information: *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSCFType removeAllObjects]: unrecognized selector sent to instance 0x10ac56f0' Thread 0 Crashed: 0 libSystem.B.dylib 0x9019ce42 __kill + 10 1 org.gnu.Emacs 0x0009267a fatal_error_signal + 314 (emacs.c:404) 2 libSystem.B.dylib 0x9019b2bb _sigtramp + 43 3 ??? 0xffffffff 0 + 4294967295 4 libSystem.B.dylib 0x9020f23a raise + 26 5 libSystem.B.dylib 0x9021b679 abort + 73 6 org.gnu.Emacs 0x0016cce5 ns_term_shutdown + 117 (nsterm.m:4025) 7 org.gnu.Emacs 0x000926cf fatal_error_signal + 399 (emacs.c:389) 8 libSystem.B.dylib 0x9019b2bb _sigtramp + 43 9 ??? 0xffffffff 0 + 4294967295 10 libobjc.A.dylib 0x94837e3b objc_exception_throw + 40 11 com.apple.CoreFoundation 0x94fca30a -[NSObject doesNotRecognizeSelector:] + 186 12 com.apple.CoreFoundation 0x94fc890c ___forwarding___ + 892 13 com.apple.CoreFoundation 0x94fc89d2 _CF_forwarding_prep_0 + 50 14 org.gnu.Emacs 0x001884ea nsfont_make_fontset_for_font + 362 (nsfont.m:1200) 15 org.gnu.Emacs 0x0018b6dd fontset_from_font + 525 (fontset.c:1694) 16 org.gnu.Emacs 0x0017475b x_new_font + 251 (nsterm.m:6376) 17 org.gnu.Emacs 0x00014098 x_set_font + 328 (frame.c:3413) 18 org.gnu.Emacs 0x00012d16 x_set_frame_parameters + 486 (frame.c:3011) 19 org.gnu.Emacs 0x00013872 Fmodify_frame_parameters + 434 (frame.c:2538) 20 org.gnu.Emacs 0x0010a598 Ffuncall + 1016 (eval.c: 3054) 21 org.gnu.Emacs 0x0014577b Fbyte_code + 3835 (bytecode.c:678) 22 org.gnu.Emacs 0x00109e21 funcall_lambda + 209 (eval.c:3236) 23 org.gnu.Emacs 0x0010a36b Ffuncall + 459 (eval.c: 3101) 24 org.gnu.Emacs 0x0010bf03 apply1 + 83 (eval.c:2798) 25 org.gnu.Emacs 0x00105c4c Fcall_interactively + 524 (callint.c:390) 26 org.gnu.Emacs 0x0010a571 Ffuncall + 977 (eval.c: 3050) If Emacs crashed, and you have the Emacs process in the gdb debugger, please include the output from the following gdb commands: `bt full' and `xbacktrace'. If you would like to further debug the crash, please read the file /Users/dr/Projects/Bazaar-Playground/emacs.cvs/nextstep/Emacs.app/ Contents/Resources/etc/DEBUG for instructions. In GNU Emacs 23.0.90.6 (i386-apple-darwin9.6.0, NS apple-appkit-949.43) of 2009-03-01 on scarlett Windowing system distributor `Apple', version 10.3.949 configured using `configure '--without-x' '--with-ns'' Important settings: value of $LC_ALL: nil value of $LC_COLLATE: nil value of $LC_CTYPE: nil value of $LC_MESSAGES: nil value of $LC_MONETARY: nil value of $LC_NUMERIC: nil value of $LC_TIME: nil value of $LANG: nil value of $XMODIFIERS: nil locale-coding-system: nil default-enable-multibyte-characters: t Major mode: Fundamental Minor modes in effect: tooltip-mode: t mouse-wheel-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t global-auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t line-number-mode: t transient-mark-mode: t Recent input: C-x 0 Recent messages: For information about GNU Emacs and the GNU system, type C-h C-a.