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Subject: Re: Newbie Problem with "missing symbols"

Re: Newbie Problem with "missing symbols"

From: Philipp Kalder <philipp_at_kalder.info>
Date: Wed, 27 Jun 2012 08:50:04 +0200

Hello,

just an update. I tried the same on a Linux VM with a very similar result.
Though the error message is different. This is either a result of different gcc versions
or the linux box just hasn't had the /usr/local/lib or /usr/local/include folder in it's PATH.

configure on the linux Box showed:

configure: summary of build options:

  version: 1.4.2
  Host type: x86_64-unknown-linux-gnu
  Install prefix: /usr/local
  Compiler: gcc
  Compiler flags: -g -O2
  Library types: Shared=yes, Static=yes
  Crypto library: openssl: no (AES-CTR: N/A) libgcrypt: yes
  Debug build: no
  Build examples: yes
  Path to sshd: (only for self-tests)
  libz compression: no

And the build with % gcc -v ssh2_agent.c -o testBuild

showed up as below. Here the arch is the same.

Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.5.2-8ubuntu4' --with-bugurl=file:///usr/share/doc/gcc-4.5/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.5 --enable-shared --enable-multiarch --with-multiarch-defaults=x86_64-linux-gnu --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib/x86_64-linux-gnu --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.5 --libdir=/usr/lib/x86_64-linux-gnu --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin --enable-gold --enable-ld=default --with-plugin-ld=ld.gold --enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu4)
COLLECT_GCC_OPTIONS='-v' '-o' 'testBuild' '-mtune=generic' '-march=x86-64'
 /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/cc1 -quiet -v ssh2_agent.c -D_FORTIFY_SOURCE=2 -quiet -dumpbase ssh2_agent.c -mtune=generic -march=x86-64 -auxbase ssh2_agent -version -fstack-protector -o /tmp/ccK5e7V7.s
GNU C (Ubuntu/Linaro 4.5.2-8ubuntu4) version 4.5.2 (x86_64-linux-gnu)
        compiled by GNU C version 4.5.2, GMP version 4.3.2, MPFR version 3.0.0-p8, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/../../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/include
 /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/include-fixed
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
GNU C (Ubuntu/Linaro 4.5.2-8ubuntu4) version 4.5.2 (x86_64-linux-gnu)
        compiled by GNU C version 4.5.2, GMP version 4.3.2, MPFR version 3.0.0-p8, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 9755ab75799195519479ef699703b13b
COLLECT_GCC_OPTIONS='-v' '-o' 'testBuild' '-mtune=generic' '-march=x86-64'
 as -V -Qy --64 -o /tmp/cc412T5h.o /tmp/ccK5e7V7.s
GNU assembler version 2.21.0 (x86_64-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.21.0.20110327
COMPILER_PATH=/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/:/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/:/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/:/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/:/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/
LIBRARY_PATH=/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/:/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/../../../:/lib/:/usr/lib/:/usr/lib/x86_64-linux-gnu/
COLLECT_GCC_OPTIONS='-v' '-o' 'testBuild' '-mtune=generic' '-march=x86-64'
 /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/collect2 --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu -dynamic-linker /lib64/ld-linux-x86-64.so.2 -z relro -o testBuild /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/../../../crt1.o /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/../../../crti.o /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/crtbegin.o -L/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2 -L/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/../../.. -L/usr/lib/x86_64-linux-gnu /tmp/cc412T5h.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/crtend.o /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/../../../crtn.o
/tmp/cc412T5h.o: In function `main':
ssh2_agent.c:(.text+0x8f): undefined reference to `libssh2_init'
ssh2_agent.c:(.text+0x185): undefined reference to `libssh2_session_init_ex'
ssh2_agent.c:(.text+0x19a): undefined reference to `libssh2_session_handshake'
ssh2_agent.c:(.text+0x1dd): undefined reference to `libssh2_hostkey_hash'
ssh2_agent.c:(.text+0x25a): undefined reference to `libssh2_userauth_list'
ssh2_agent.c:(.text+0x2c2): undefined reference to `libssh2_agent_init'
ssh2_agent.c:(.text+0x309): undefined reference to `libssh2_agent_connect'
ssh2_agent.c:(.text+0x349): undefined reference to `libssh2_agent_list_identities'
ssh2_agent.c:(.text+0x394): undefined reference to `libssh2_agent_get_identity'
ssh2_agent.c:(.text+0x3f1): undefined reference to `libssh2_agent_userauth'
ssh2_agent.c:(.text+0x4aa): undefined reference to `libssh2_channel_open_ex'
ssh2_agent.c:(.text+0x4ff): undefined reference to `libssh2_channel_setenv_ex'
ssh2_agent.c:(.text+0x53d): undefined reference to `libssh2_channel_request_pty_ex'
ssh2_agent.c:(.text+0x588): undefined reference to `libssh2_channel_process_startup'
ssh2_agent.c:(.text+0x5c5): undefined reference to `libssh2_channel_free'
ssh2_agent.c:(.text+0x5d9): undefined reference to `libssh2_agent_disconnect'
ssh2_agent.c:(.text+0x5e5): undefined reference to `libssh2_agent_free'
ssh2_agent.c:(.text+0x607): undefined reference to `libssh2_session_disconnect_ex'
ssh2_agent.c:(.text+0x613): undefined reference to `libssh2_session_free'
ssh2_agent.c:(.text+0x632): undefined reference to `libssh2_exit'
collect2: ld returned 1 exit status

On Jun 26, 2012, at 8:07 PM, Philipp Kalder wrote:

> Hello there,
>
> I'm just starting out getting deeper into a "curly bracket" Language. So I'm a fairly
> unexperienced in debugging gcc/linker messages. Sadly this is what I get trying to
> compile even an libssh2 sample.
>
> I'm mostly coding in Python, from small scripts up to more complex, Object Oriented
> stuff. For the smaller scripts I wrote a convenience wrapper around the python lib
> Paramiko which is a library around ssh and the likes. Being able to execute commands
> via ssh and parse the results is at the core of the most scripts I write. So I thought this
> to be a good starting point for learning C/ Objective-C. Asking the Interwebs I found
> libssh2 to be the proper library for this. However, after grabbing the latest tar-ball and compiling
> it with the three-step:
>
> ./configure
> (Here the summary of configure)
> configure: summary of build options:
>
> version: 1.4.2
> Host type: x86_64-apple-darwin11.4.0
> Install prefix: /usr/local
> Compiler: gcc
> Compiler flags: -DLIBSSH2_DARWIN
> Library types: Shared=yes, Static=yes
> Crypto library: openssl: yes (AES-CTR: no) libgcrypt: no
> Debug build: no
> Build examples: yes
> Path to sshd: /usr/sbin/sshd (only for self-tests)
> libz compression: yes
>
> make
>
> make install
>
> I find myself stuck with a linker error that I just cannot solve. I "googled" a lot and found others with
> similar, yet not the same problem. And most of the time the answer/solution was a bit too much for
> me. Yet I have a suspicion that the solution is much simpler than I expect. As it seems for to be a
> problem with the arch of the host. My Mac is a x86_64 machine and configure figured that one out
> all right. But after I assembled a test programm, that was not complete but at a point where I could
> try to build it, I got errors. So I decided to try and build an example that was provided (and already build)
> with the tar-ball. But I get the same errors:
>
> Undefined symbols for architecture x86_64:
> "_libssh2_init", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_session_init_ex", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_session_handshake", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_hostkey_hash", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_userauth_list", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_agent_init", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_agent_connect", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_agent_list_identities", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_agent_get_identity", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_agent_userauth", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_channel_open_ex", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_channel_setenv_ex", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_channel_request_pty_ex", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_channel_process_startup", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_channel_free", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_agent_disconnect", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_agent_free", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_session_disconnect_ex", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_session_free", referenced from:
> _main in cc6PUHa5.o
> "_libssh2_exit", referenced from:
> _main in cc6PUHa5.o
> ld: symbol(s) not found for architecture x86_64
> collect2: ld returned 1 exit status
>
> ---
>
> I tried running gcc with verbosity on which yielded, on top of the above output:
>
> Using built-in specs.
> Target: i686-apple-darwin11
> Configured with: /private/var/tmp/llvmgcc42/llvmgcc42-2336.9~22/src/configure --disable-checking --enable-werror --prefix=/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2 --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-prefix=llvm- --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib --build=i686-apple-darwin11 --enable-llvm=/private/var/tmp/llvmgcc42/llvmgcc42-2336.9~22/dst-llvmCore/Developer/usr/local --program-prefix=i686-apple-darwin11- --host=x86_64-apple-darwin11 --target=i686-apple-darwin11 --with-gxx-include-dir=/usr/include/c++/4.2.1
> Thread model: posix
> gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.9.00)
> /usr/llvm-gcc-4.2/bin/../libexec/gcc/i686-apple-darwin11/4.2.1/cc1 -quiet -v -imultilib x86_64 -iprefix /usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/ -D__DYNAMIC__ ssh2_agent.c -fPIC -quiet -dumpbase ssh2_agent.c -mmacosx-version-min=10.7.4 -m64 -mtune=core2 -auxbase ssh2_agent -version -o /var/folders/bj/kx0hd0fd405cspwp6g9tvh5w0000gn/T//ccRkCGdH.s
> ignoring nonexistent directory "/usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/../../../../i686-apple-darwin11/include"
> ignoring nonexistent directory "/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1/../../../../i686-apple-darwin11/include"
> #include "..." search starts here:
> #include <...> search starts here:
> /usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/include
> /usr/local/include
> /Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1/include
> /usr/include
> /System/Library/Frameworks (framework directory)
> /Library/Frameworks (framework directory)
> End of search list.
> GNU C version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.9.00) (i686-apple-darwin11)
> compiled by GNU C version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.9.00).
> GGC heuristics: --param ggc-min-expand=150 --param ggc-min-heapsize=131072
> Compiler executable checksum: ee05ffc2102727aa16c85f6ae97aa56c
> /usr/llvm-gcc-4.2/bin/../libexec/gcc/i686-apple-darwin11/4.2.1/as -arch x86_64 -force_cpusubtype_ALL -o /var/folders/bj/kx0hd0fd405cspwp6g9tvh5w0000gn/T//ccZFQXlh.o /var/folders/bj/kx0hd0fd405cspwp6g9tvh5w0000gn/T//ccRkCGdH.s
> /usr/llvm-gcc-4.2/bin/../libexec/gcc/i686-apple-darwin11/4.2.1/collect2 -dynamic -arch x86_64 -macosx_version_min 10.7.4 -weak_reference_mismatches non-weak -o testBuild -lcrt1.10.6.o -L/usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/x86_64 -L/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1/x86_64 -L/usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1 -L/usr/llvm-gcc-4.2/bin/../lib/gcc -L/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1 -L/usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/../../.. -L/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1/../../.. /var/folders/bj/kx0hd0fd405cspwp6g9tvh5w0000gn/T//ccZFQXlh.o -lSystem -lgcc -lSystem
>
>
> ---
>
> So what got my attention was that gcc said:
> Target: i686-apple-darwin11
>
> Where as configure said:
> Host type: x86_64-apple-darwin11.4.0
>
> And I tried building the lib with
>
> ./configure --build=i686_64-apple-darwin11
>
> which finished successfully but gcc yields the same results.
>
> So after a very long text I'm still stuck with:
> ld: symbol(s) not found for architecture x86_64
>
> Another hint, Xcode yields also something about the linker.
> Unfortunately I'm writing this email on another mac as where I encountered the problem first.
> ATM I'm unable to make Xcode on this machine find libssh2.h. But that is a problem to ignore.
>
> So the question of the day, does anybody know what's wrong here? Wht do I need to change
> to be able to even build the samples provided?
>
> Best Regards,
> Philipp
>
>
>
>
> _______________________________________________
> libssh2-devel http://cool.haxx.se/cgi-bin/mailman/listinfo/libssh2-devel
>

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Received on 2012-06-27

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