I just tried to compile package gnugk-2.2.3-2 from Suse Linux with a recent GNU C compiler version 4.2 snapshot 20060114.
The compiler snapshot said /home/dcb/gnu/42-20060114/results/bin/g++ -g -O3 -Wall -fmessage-length=0 -DHAS_RADIUS=1 -DHAS_MSG_NOSIGNAL=1 -D'MANUFACTURER=GNU' -D'PROGRAMMNAME=Gatekeeper' -DPTRACING -D_REENTRANT -Wall -O2 -g -fmessage-length=0 -D_FORTIFY_SOURCE=2 -fexceptions -DP_64BIT -I/usr/share/pwlib//include -DPTRACING -I/usr/include/openh323 -DMAJOR_VERSION=2 -DMINOR_VERSION=2 -DBUILD_NUMBER=3 -Os -felide-constructors -x c++ -c main.cxx -o obj_linux_x86_64_r/main.o /usr/include/ptlib/notifier.h: In constructor 'PNotifierFunction::PNotifierFunction(void*)': /usr/include/ptlib/notifier.h:42: internal compiler error: tree check: expected tree that contains 'decl with visibility' structure, have 'parm_decl' in c_common_truthvalue_conversion, at c-common.c:2430 Please submit a full bug report, with preprocessed source if appropriate. See <URL:http://gcc.gnu.org/bugs.html> for instructions. make: *** [obj_linux_x86_64_r/main.o] Error 1 Preprocessed source code attached. -- Summary: tree check fail at c-common.c:2430 Product: gcc Version: 4.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: dcb314 at hotmail dot com GCC host triplet: x86_64-suse-linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25861