When I was using "make -j8" on an ia64 machine with 16 processors, I got
[EMAIL PROTECTED] gcc]$ grep O2g.gch nohup.out /export/build/gnu/gcc/build-ia64-linux/./gcc/xgcc -shared-libgcc -B/export/build/gnu/gcc/build-ia64-linux/./gcc -nostdinc++ -L/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/src -L/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/src/.libs -B/usr/gcc-4.3/ia64-unknown-linux-gnu/bin/ -B/usr/gcc-4.3/ia64-unknown-linux-gnu/lib/ -isystem /usr/gcc-4.3/ia64-unknown-linux-gnu/include -isystem /usr/gcc-4.3/ia64-unknown-linux-gnu/sys-include -Winvalid-pch -Wno-deprecated -x c++-header -g -O2 -D_GNU_SOURCE -I/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/include/ia64-unknown-linux-gnu -I/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/include -I/net/gnu-13/export/gnu/src/gcc/gcc/libstdc++-v3/libsupc++ -O2 -g /net/gnu-13/export/gnu/src/gcc/gcc/libstdc++-v3/include/precompiled/stdc++.h -o ia64-unknown-linux-gnu/bits/stdc++.h.gch/O2g.gch /export/build/gnu/gcc/build-ia64-linux/./gcc/xgcc -shared-libgcc -B/export/build/gnu/gcc/build-ia64-linux/./gcc -nostdinc++ -L/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/src -L/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/src/.libs -B/usr/gcc-4.3/ia64-unknown-linux-gnu/bin/ -B/usr/gcc-4.3/ia64-unknown-linux-gnu/lib/ -isystem /usr/gcc-4.3/ia64-unknown-linux-gnu/include -isystem /usr/gcc-4.3/ia64-unknown-linux-gnu/sys-include -Winvalid-pch -Wno-deprecated -x c++-header -g -O2 -D_GNU_SOURCE -I/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/include/ia64-unknown-linux-gnu -I/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/include -I/net/gnu-13/export/gnu/src/gcc/gcc/libstdc++-v3/libsupc++ -O2 -g /net/gnu-13/export/gnu/src/gcc/gcc/libstdc++-v3/include/precompiled/stdtr1c++.h -o ia64-unknown-linux-gnu/bits/stdtr1c++.h.gch/O2g.gch /export/build/gnu/gcc/build-ia64-linux/./gcc/xgcc -shared-libgcc -B/export/build/gnu/gcc/build-ia64-linux/./gcc -nostdinc++ -L/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/src -L/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/src/.libs -B/usr/gcc-4.3/ia64-unknown-linux-gnu/bin/ -B/usr/gcc-4.3/ia64-unknown-linux-gnu/lib/ -isystem /usr/gcc-4.3/ia64-unknown-linux-gnu/include -isystem /usr/gcc-4.3/ia64-unknown-linux-gnu/sys-include -Winvalid-pch -Wno-deprecated -x c++-header -g -O2 -D_GNU_SOURCE -I/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/include/ia64-unknown-linux-gnu -I/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/include -I/net/gnu-13/export/gnu/src/gcc/gcc/libstdc++-v3/libsupc++ -O2 -g /net/gnu-13/export/gnu/src/gcc/gcc/libstdc++-v3/include/precompiled/extc++.h -o ia64-unknown-linux-gnu/bits/extc++.h.gch/O2g.gch make[4]: *** [ia64-unknown-linux-gnu/bits/extc++.h.gch/O2g.gch] Error 1 /export/build/gnu/gcc/build-ia64-linux/./gcc/xgcc -shared-libgcc -B/export/build/gnu/gcc/build-ia64-linux/./gcc -nostdinc++ -L/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/src -L/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/src/.libs -B/usr/gcc-4.3/ia64-unknown-linux-gnu/bin/ -B/usr/gcc-4.3/ia64-unknown-linux-gnu/lib/ -isystem /usr/gcc-4.3/ia64-unknown-linux-gnu/include -isystem /usr/gcc-4.3/ia64-unknown-linux-gnu/sys-include -Winvalid-pch -Wno-deprecated -x c++-header -g -O2 -D_GNU_SOURCE -I/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/include/ia64-unknown-linux-gnu -I/export/build/gnu/gcc/build-ia64-linux/ia64-unknown-linux-gnu/libstdc++-v3/include -I/net/gnu-13/export/gnu/src/gcc/gcc/libstdc++-v3/libsupc++ -O2 -g /net/gnu-13/export/gnu/src/gcc/gcc/libstdc++-v3/include/precompiled/extc++.h -o ia64-unknown-linux-gnu/bits/extc++.h.gch/O2g.gch make[6]: *** [ia64-unknown-linux-gnu/bits/extc++.h.gch/O2g.gch] Error 1 [EMAIL PROTECTED] gcc]$ That is the target, ia64-unknown-linux-gnu/bits/extc++.h.gch/O2g.gch, was made twice at the same time and they ran into each other. -- Summary: libstdc++ isn't parallel build safe Product: gcc Version: 4.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: hjl at lucon dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30674