when i did ldd -r /usr/local/lib/opencog/libquery.so, i got few undefined symbols, which i think probably linkage errors.
linux-vdso.so.1 => (0x00007ffcfeb99000)
libatomutils.so => /usr/local/lib/opencog/libatomutils.so (0x00007fb2fe6b2000)
liblambda.so => /usr/local/lib/opencog/liblambda.so (0x00007fb2fe498000)
libatomspace.so => /usr/local/lib/opencog/libatomspace.so (0x00007fb2fe237000)
libsmob.so => /usr/local/lib/opencog/libsmob.so (0x00007fb2fe00f000)
libatomcore.so => /usr/local/lib/opencog/libatomcore.so (0x00007fb2fdde0000)
libatombase.so => /usr/local/lib/opencog/libatombase.so (0x00007fb2fdba7000)
libtruthvalue.so => /usr/local/lib/opencog/libtruthvalue.so (0x00007fb2fd996000)
libguile-2.0.so.22 => /usr/lib/libguile-2.0.so.22 (0x00007fb2fd5f6000)
libcogutil.so => /usr/local/lib/libcogutil.so (0x00007fb2fd395000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fb2fd091000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fb2fce7b000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fb2fcab5000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fb2fc897000)
/lib64/ld-linux-x86-64.so.2 (0x0000561927525000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fb2fc590000)
libgc.so.1 => /usr/lib/x86_64-linux-gnu/libgc.so.1 (0x00007fb2fc324000)
libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6 (0x00007fb2fc11b000)
libunistring.so.0 => /usr/lib/x86_64-linux-gnu/libunistring.so.0 (0x00007fb2fbe06000)
libgmp.so.10 => /usr/lib/x86_64-linux-gnu/libgmp.so.10 (0x00007fb2fbb92000)
libltdl.so.7 => /usr/lib/x86_64-linux-gnu/libltdl.so.7 (0x00007fb2fb988000)
libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007fb2fb74e000)
libboost_filesystem.so.1.54.0 => /usr/lib/x86_64-linux-gnu/libboost_filesystem.so.1.54.0 (0x00007fb2fb538000)
libboost_system.so.1.54.0 => /usr/lib/x86_64-linux-gnu/libboost_system.so.1.54.0 (0x00007fb2fb334000)
libboost_regex.so.1.54.0 => /usr/lib/x86_64-linux-gnu/libboost_regex.so.1.54.0 (0x00007fb2fb02c000)
libgomp.so.1 => /usr/lib/x86_64-linux-gnu/libgomp.so.1 (0x00007fb2faafa000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fb2fa8f5000)
libicuuc.so.52 => /usr/lib/x86_64-linux-gnu/libicuuc.so.52 (0x00007fb2fa57c000)
libicui18n.so.52 => /usr/lib/x86_64-linux-gnu/libicui18n.so.52 (0x00007fb2fa174000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007fb2f9f5b000)
libicudata.so.52 => /usr/lib/x86_64-linux-gnu/libicudata.so.52 (0x00007fb2f86ee000)
undefined symbol: _ZN7opencog14EvaluationLink15do_eval_scratchEPNS_9AtomSpaceERKNS_6HandleES2_b (/usr/local/lib/opencog/libquery.so)
undefined symbol: _ZN7opencog14EvaluationLink11do_evaluateEPNS_9AtomSpaceERKNS_6HandleEb (/usr/local/lib/opencog/libquery.so)
undefined symbol: _ZN7opencog12Instantiator11instantiateERKNS_6HandleERKSt3mapIS1_S1_St4lessIS1_ESaISt4pairIS2_S1_EEE (/usr/local/lib/opencog/libquery.so)
But the thing is, i have newly installed and built atomspace, cogutils and opencog in a new laptop. Still i got the unbound variable error.