When updating a source try (through contrib/gcc_update) and typing make in the build directory configure recheck fails often for the runtime libraries (libc++-v3, libjava, boehmgc, libffi, etc.) Here is an example for libmudflap:
make[1]: Entering directory `/home/mark/src/gcc-obj/i686-pc-linux-gnu/libmudflap' /bin/sh ./config.status --recheck running /bin/sh /home/mark/src/gcc/libmudflap/configure --cache-file=./config.cache --host=i686-pc-linux-gnu --build=i686-pc-linux-gnu --enable-multilib --enable-java-awt=gtk --prefix=/usr/local/gcc35 --with-gcc-version-trigger=/home/mark/src/gcc/gcc/version.c --enable-languages=c,c++,java --program-transform-name=s,y,y, --srcdir=../../../gcc/libmudflap --with-target-subdir=i686-pc-linux-gnu CPPFLAGS=-O2 -g -O2 build_alias=i686-pc-linux-gnu host_alias=i686-pc-linux-gnu --no-create --no-recursion configure: loading cache ./config.cache configure: error: `target_alias' was not set in the previous run configure: error: changes in the environment can compromise the build configure: error: run `make distclean' and/or `rm ./config.cache' and start overmake[1]: *** [config.status] Error 1 make[1]: Leaving directory `/home/mark/src/gcc-obj/i686-pc-linux-gnu/libmudflap'make: *** [all-target-libmudflap] Error 2 A workaround is deleting that whole subdirectory and trying make from the toplevel build directory again. -- Summary: remaking existing build after cvs update gives configure recheck problems Product: gcc Version: 4.0.0 Status: UNCONFIRMED Severity: normal Priority: P2 Component: bootstrap AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: mark at gcc dot gnu dot org CC: gcc-bugs at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18288