[Buildroot] libcapn build failure

[Johan Sagaert <sagaert.johan@proximus.be>]

Dear Samuel

Op 16/02/2016 om 14:27 schreef Samuel Martin:
> Hi Johan,
>
>
> On Feb 15, 2016 5:13 PM, "Johan Sagaert"<sagaert.johan@proximus.be>  wrote:
>> Hi
>>
>> I am trying to get libcapn into buildroot.(cmake based)
>> Build error :
>>
>>>>> libcapn 7a6dc662e9daa864f687 Configuring
>> (mkdir -p /home/buildroot12git/output/build/libcapn-7a6dc662e9daa864f687/ && cd /home/buildroot12git/output/build/libcapn-7a6dc662e9daa864f687/ && rm -f CMakeCache.txt && PATH="/home/buildroot12git/output/host/bin:/home/buildroot12git/output/host/sbin:/home/buildroot12git/output/host/usr/bin:/home/buildroot12git/output/host/usr/sbin:/root/google-cloud-sdk/bin:/home/buildroot12git/output/host/usr/bin:/home/buildroot12git/output/build/host-cmake-3.1.3/bin:/root/google-cloud-sdk/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin" /home/buildroot12git/output/host/usr/bin/cmake /home/buildroot12git/output/build/libcapn-7a6dc662e9daa864f687/ -DCMAKE_TOOLCHAIN_FILE="/home/buildroot12git/output/host/usr/share/buildroot/toolchainfile.cmake" -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX="/usr" -DCMAKE_COLOR_MAKEFILE=OFF -DBUILD_DOC=OFF -DBUILD_DOCS=OFF -DBUILD_EXAMPLE=OFF -DBUILD_EXAMPLES=OFF -DBUILD_TEST=OFF -DBUILD_TESTS=OFF -DB
>> UILD_TESTING=OFF -DBUILD_SHARED_LIBS=ON -DUSE_CCACHE=OFF  )
>> -- Looking for include file ctype.h
>> -- Looking for include file ctype.h - found
>> -- Looking for include file inttypes.h
>> -- Looking for include file inttypes.h - found
>> -- Looking for include file stdint.h
>> -- Looking for include file stdint.h - found
>> -- Looking for include file unistd.h
>> -- Looking for include file unistd.h - found
>> -- Looking for include file netinet/in.h
>> -- Looking for include file netinet/in.h - found
>> -- Looking for include file arpa/inet.h
>> -- Looking for include file arpa/inet.h - found
>> -- Looking for include file netdb.h
>> -- Looking for include file netdb.h - found
>> -- Looking for include file sys/fcntl.h
>> -- Looking for include file sys/fcntl.h - found
>> -- Looking for include file sys/socket.h
>> -- Looking for include file sys/socket.h - found
>> -- Looking for include file strings.h
>> -- Looking for include file strings.h - found
>> -- Looking for strerror_r
>> -- Looking for strerror_r - found
>> -- Performing test APN_HAVE_GLIBC_STRERROR_R
>> CMake Error: TRY_RUN() invoked in cross-compiling mode, please set the following cache variables appropriately:
>>     APN_HAVE_GLIBC_STRERROR_R (advanced)
>>     APN_HAVE_GLIBC_STRERROR_R__TRYRUN_OUTPUT (advanced)
>> For details see /home/buildroot12git/output/build/libcapn-7a6dc662e9daa864f687/TryRunResults.cmake
>> -- Performing test APN_HAVE_GLIBC_STRERROR_R - Failed
>> -- Performing test APN_HAVE_POSIX_STRERROR_R
>> CMake Error: TRY_RUN() invoked in cross-compiling mode, please set the following cache variables appropriately:
>>     APN_HAVE_POSIX_STRERROR_R (advanced)
>>     APN_HAVE_POSIX_STRERROR_R__TRYRUN_OUTPUT (advanced)
>> For details see /home/buildroot12git/output/build/libcapn-7a6dc662e9daa864f687/TryRunResults.cmake
>> -- Performing test APN_HAVE_POSIX_STRERROR_R - Failed
>> -- Found OpenSSL: /home/buildroot12git/output/host/usr/arm-buildroot-linux-gnueabi/sysroot/usr/lib/libssl.so;/home/buildroot12git/output/host/usr/arm-buildroot-linux-gnueabi/sysroot/usr/lib/libcrypto.so (found version "1.0.2c")
>> -- Configuring incomplete, errors occurred!
>> See also "/home/buildroot12git/output/build/libcapn-7a6dc662e9daa864f687/CMakeFiles/CMakeOutput.log".
>> make: *** [/home/buildroot12git/output/build/libcapn-7a6dc662e9daa864f687/.stamp_configured] Error 1
>>
>>
>>
>> I have no clue how to set cache variables appropriately...
>>
>> (Due to the git submodule usage, i had to clone it first some where else and then
>> executed  git submodule update --init , and then i copied the 3rd party source into my build tree
>> in order to get the jansson source)
>>
>> See attached logfiles
>>
>>
>> almost giving up
> Don't! This part of the learning process ;-)
>
> Few tips for investigating cmake package failures:
> 1) the log files generated by cmake (i.e. the *.error and *.output
> files) are good starting points;
> 2) after configuring, you can check the CMakeCache.txt file (located
> in the build directory) to see what is the value of this or that
> variable;
> 3) you can set/force some variables for the configure step by adding
> some *_CONF_OPTS (see [1]), e.g.:
>        MYPKG_CONF_OPTS += -Dvarfoo=value
> 4) some variables may not be stored in the CMakeCache.txt file, or if
> you want to trace some cmake code path, you can patch the
> CMakeLists.txt files calling the message function [2] (similar to
> adding printf in the code);
> 5) a last thing when having trouble with some dependency modules, you
> may need to add --trace to the cmake options [3]. This is not what you
> need here.
>
> Of course, trying to do run test in the buildroot case is a complete non-sense.
>
> For your issue, you should start with tips 2), 3) and maybe 4).
>
> For this specific HAVE_*_STRERROR test, you may need to set those
> corresponding cmake variables differently, depending on the C-library
> used in the toolchain.
>
> [...]
>> ==========
>> libcapn.mk :
>> ==========
>> ################################################################################
>> #
>> # libcapn
>> #
>> ################################################################################
>>
>> LIBCAPN_VERSION = 7a6dc662e9daa864f687
>> LIBCAPN_SITE = $(call github,adobkin,libcapn,$(LIBCAPN_VERSION))
>> LIBCAPNLICENSE = MIT
>>
>> LIBCAPN_DEPENDENCIES += jansson openssl
>>
>> $(eval $(cmake-package))
> This looks right; try playing with (values are set randomly here ;-]):
> LIBCAPN_CONF_OPTS = -DAPN_HAVE_GLIBC_STRERROR_R=ON \
>    -DAPN_HAVE_POSIX_STRERROR_R=OFF
>
> This should bypass the tryrun test.
>
> Good luck ;-)
>
>
> [1]http://nightly.buildroot.org/manual.html#cmake-package-reference
> [2]https://cmake.org/cmake/help/v3.4/command/message.html
> [3]https://cmake.org/cmake/help/v3.4/manual/cmake.1.html
>
>
> Regards,
>
> --
> Samuel
>
Thanks for keeping me motivated

There are several problems with this package.
 From the  README.md :

git clonehttps://github.com/adobkin/libcapn.git
git submodule update --init      <<<---------- This downloads the jansson source.

For this to work in buildroot with git, the .git directory needs to be available in order to execute
the submodule update.
So i think i will have to do this step outside of buildroot, and then tar.bz2 the whole thing,
in order to use it from the libcapn.mk

  So i did this outside of the buildroot build directory.

cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_TOOLCHAIN_FILE= \
"/home/buildroot12git/output/host/usr/share/buildroot/toolchainfile.cmake" \
  -DCMAKE_INSTALL_PREFIX=/home/buildroot12git/output/staging/usr -DUSE_CCACHE=OFF \
  -DAPN_HAVE_GLIBC_STRERROR_R=OFF -DAPN_HAVE_POSIX_STRERROR_R=OFF \
  -DAPN_HAVE_GLIBC_STRERROR_R__TRYRUN_OUTPUT=OFF -DAPN_HAVE_POSIX_STRERROR_R__TRYRUN_OUTPUT=OFF

This brings me somewhat closer , but  there seems to be a problem with 
the jansson not
being built for the (ARM) target:


Scanning dependencies of target test_unpack
[100%] Building C object 
CMakeFiles/test_unpack.dir/test/suites/api/test_unpack.c.o
Linking C executable bin/test_unpack
[100%] Built target test_unpack
[ 35%] No install step for 'jansson'
[ 40%] Completed 'jansson'
[ 40%] Built target jansson
Scanning dependencies of target capn
[ 45%] Building C object CMakeFiles/capn.dir/src/library/apn_memory.c.o
[ 50%] Building C object CMakeFiles/capn.dir/src/library/apn.c.o
[ 55%] Building C object CMakeFiles/capn.dir/src/library/apn_strings.c.o
[ 60%] Building C object CMakeFiles/capn.dir/src/library/apn_payload.c.o
[ 65%] Building C object CMakeFiles/capn.dir/src/library/apn_tokens.c.o
[ 70%] Building C object 
CMakeFiles/capn.dir/src/library/apn_binary_message.c.o
[ 75%] Building C object CMakeFiles/capn.dir/src/library/apn_array.c.o
[ 80%] Building C object CMakeFiles/capn.dir/src/library/apn_strerror.c.o
[ 85%] Building C object CMakeFiles/capn.dir/src/library/apn_ssl.c.o
[ 90%] Building C object CMakeFiles/capn.dir/src/library/apn_log.c.o
Linking C shared library lib/Release/libcapn.so
/home/buildroot12git/output/host/usr/lib/gcc/arm-buildroot-linux-gnueabi/4.9.3/../../../../arm-buildroot-linux-gnueabi/bin/ld: 
src/third_party/jansson/lib/libjansson.a(value.c.o): Relocations in 
generic ELF (EM: 3)
/home/buildroot12git/output/host/usr/lib/gcc/arm-buildroot-linux-gnueabi/4.9.3/../../../../arm-buildroot-linux-gnueabi/bin/ld: 
src/third_party/jansson/lib/libjansson.a(value.c.o): Relocations in 
generic ELF (EM: 3)
src/third_party/jansson/lib/libjansson.a: error adding symbols: File in 
wrong format
collect2: error: ld returned 1 exit status
make[2]: *** [lib/Release/libcapn.so.2.0.0] Error 1
make[1]: *** [CMakeFiles/capn.dir/all] Error 2
make: *** [all] Error 2

Then i did some tweaking in the generated link.txt files.(quick and 
dirty solution)

sed -i 's/src\/third_party\/jansson\/lib\/libjansson.a/-ljansson/g' 
./CMakeFiles/apn-pusher.dir/link.txt
sed -i 's/src\/third_party\/jansson\/lib\/libjansson.a/-ljansson/g' 
./CMakeFiles/capn.dir/link.txt

Linking C executable apn-pusher
[ 95%] Built target apn-pusher
Scanning dependencies of target libcapn-config
[100%] Building C object 
CMakeFiles/libcapn-config.dir/src/config/apn_config.c.o
Linking C executable libcapn-config
[100%] Built target libcapn-config

I guess i need to apply some patches to the 
src/third_party/jansson/CMakeLists.txt
unless some -D options could do the job.

Best Regards
Johan