Make error: failed to link with libgflags.a

[rantonels]

/bin/bash ./libtool  --tag=CXX   --mode=link g++    -Wall -Wwrite-strings -Woverloaded-virtual -Wno-sign-compare  -DNO_FRAME_POINTER  -DNDEBUG -g -O2    -o libglog.la -rpath /usr/local/lib  src/libglog_la-logging.lo src/libglog_la-raw_logging.lo src/libglog_la-vlog_is_on.lo src/libglog_la-utilities.lo src/libglog_la-demangle.lo src/libglog_la-symbolize.lo src/libglog_la-signalhandler.lo   -lgflags  -lpthread 
libtool: link: g++  -fPIC -DPIC -shared -nostdlib /usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/4.9/crtbeginS.o  src/.libs/libglog_la-logging.o src/.libs/libglog_la-raw_logging.o src/.libs/libglog_la-vlog_is_on.o src/.libs/libglog_la-utilities.o src/.libs/libglog_la-demangle.o src/.libs/libglog_la-symbolize.o src/.libs/libglog_la-signalhandler.o   -lgflags -lpthread -L/usr/lib/gcc/x86_64-linux-gnu/4.9 -L/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/4.9/../../.. -lstdc++ -lm -lc -lgcc_s /usr/lib/gcc/x86_64-linux-gnu/4.9/crtendS.o /usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/crtn.o  -O2   -Wl,-soname -Wl,libglog.so.0 -o .libs/libglog.so.0.0.0
/usr/bin/ld: //usr/local/lib/libgflags.a(gflags.cc.o): relocation R_X86_64_32 against `.rodata.str1.1' can not be used when making a shared object; recompile with -fPIC
//usr/local/lib/libgflags.a: error adding symbols: Bad value
collect2: error: ld returned 1 exit status
Makefile:1041: recipe for target 'libglog.la' failed
make: *** [libglog.la] Error 1

note that it searches for the library at

//usr/local/lib/libgflags.a

[VictorLamoine]

Similar to #45.

gflags is not compiled as a shared library by default; make sure it is compiled as a shared library:

cd gflags/build
cmake .. -DBUILD_SHARED_LIBS=ON
make -j2
sudo make -j2 install

After that glog compiles fine against gflags.

[pearlmary]

/usr/bin/ld: warning: libgflags.so.2, needed by /usr/local/lib/libglog.so, not found (try using -rpath or -rpath-link)
/usr/local/lib/libglog.so: undefined reference to `google::FlagRegisterer::FlagRegisterer(char const*, char const*, char const*, char const*, void*, void*)'
collect2: error: ld returned 1 exit status
Makefile:625: recipe for target '.build_debug/tools/extract_features.bin' failed
make: *** [.build_debug/tools/extract_features.bin] Error 1

[pearlmary]

how to solve this
i have been installing caffe for months now