On Tue, Jun 29, 2021 at 10:23 AM Jonathan Wakely <jwakely.gcc@xxxxxxxxx> wrote: > > > On Tue, 29 Jun 2021, 17:57 Oleg Smolsky, <osmolsky@xxxxxxxxxxxx> wrote: > >> Thank you for the hints, Jonathan! >> >> The command is indeed g++, invoked via >> automake/libtool: /opt/gcc-11/bin/g++ -g -Wall -fno-omit-frame-pointer >> -gdwarf-4 -O2 -Werror -std=c++17 -Wl,-rpath -Wl,/opt/gcc-11/lib64 >> -Wl,-rpath -Wl,/opt/3p/lib -o ns_conn_test >> libs/netsvc/test/ns_conn_test/src/cpp/NsConnTest.o -L/opt/3p/lib >> ./.libs/libnsevent.a /opt/3p/lib/libzmq.so >> /opt/gcc-9/lib/../lib64/libstdc++.so /opt/gcc-11/lib/../lib64/libstdc++.so >> -lpthread -lrt -ldl -lm -lz -Wl,-rpath -Wl,/opt/3p/lib -Wl,-rpath >> -Wl,/opt/gcc-9/lib/../lib64 -Wl,-rpath -Wl,/opt/gcc-11/lib/../lib64 >> -Wl,-rpath -Wl,/opt/3p/lib -Wl,-rpath -Wl,/opt/gcc-9/lib/../lib64 >> -Wl,-rpath -Wl,/opt/gcc-11/lib/../lib64 >> > > Yikes! Yeah, libtool has really created a mess here. > Yes! For the record, the issue was caused by a funky transformation that the automake/libtool build system does when it sees `-lfoo` and finds a ` libfoo.la` somewhere in the lib path. The ".la" file is generated by every automake/libtool-based build system that produces libraries and is installed with `make install` by default. Hopefully this note will save someone a bit of time down the road. The debugging steps are: - `make your-target V=1` to see the compiler options for the linking step - check whether your own `-lfoo` is magically converted into `...../libfoo.so ..../libstdc++.so` This happens when using GCC installed into a non-standard path (as it forces users to bake libstdc++ path into ELF files with the `-Wl,--rpath,....` option) and mixing compiler versions. Oleg. >
