Bug appears to be related to software build and linked against different version of libz:
Analysis: Output of ld when trying to build an application that uses libpng16: /usr/lib/x86_64-linux-gnu/libpng16.so.16: undefined reference to `inflateReset2@ZLIB_1.2.3.4' /usr/lib/x86_64-linux-gnu/libpng16.so.16: undefined reference to `inflateValidate@ZLIB_1.2.9' Output of ldd (same output as above): > ldd /usr/lib/x86_64-linux-gnu/libpng16.so.16 linux-vdso.so.1 (0x00007ffeda752000) libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f0dd35dd000) libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f0dd323f000) libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f0dd2e4e000) /lib64/ld-linux-x86-64.so.2 (0x00007f0dd3a2c000) checking for missing symbols: > readelf --syms /usr/lib/x86_64-linux-gnu/libpng16.so.16 | grep inflateReset2 9: 0000000000000000 0 FUNC GLOBAL DEFAULT UND inflateReset2@ZLIB_1.2.3.4 (4) Ok, symbol appears to be there. Why does ld pop up the error? --> linker command line references an older z-lib earlier on in the library dependencies -> hence, zlib from system is not used (though required by libpng16). Solution: remove linker dependency to custom libz (remove "-lz") and try linking against system libz. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1780233 Title: libpng16-16 needs ZLIB_1.2.9 but package does not install it To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libpng1.6/+bug/1780233/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs