Tests fail to build when preferring external compressors in non-system locations

[leifwalsh]

Since the tests link with the library name blosc_testing rather than linking with the target name blosc_shared_testing, CMake doesn't locate the other libs linked into blosc_shared_testing.

c-blosc/tests/CMakeLists.txt

Line 74 in cca8a96

target_link_libraries(${target} blosc_testing)

This fails to find the compressor libraries when linking the tests:

...
[ 59%] Linking C executable test_shuffle_roundtrip_sse2
/path/to/ld.bfd: warning: liblz4.so.1, needed by /path/to/build/blosc/libblosc_testing.so, not found (try using -rpath or -rpath-link)
/path/to/ld.bfd: warning: libsnappy.so.1, needed by /path/to/build/blosc/libblosc_testing.so, not found (try using -rpath or -rpath-link)
/path/to/ld.bfd: warning: libz.so.1, needed by /path/to/build/blosc/libblosc_testing.so, not found (try using -rpath or -rpath-link)
/path/to/ld.bfd: warning: libzstd.so.1.3.3, needed by /path/to/build/blosc/libblosc_testing.so, not found (try using -rpath or -rpath-link)
/path/to/build/blosc/libblosc_testing.so: undefined reference to `LZ4_compress_HC'

 % ldd /path/to/build/blosc/libblosc_testing.so
        linux-vdso.so.1 =>  (0x00007f52a8132000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f52a7ce8000)
        liblz4.so.1 => /path/to/lz4/lib/liblz4.so.1 (0x00007f52a7ad1000)
        libsnappy.so.1 => /path/to/snappy/lib/libsnappy.so.1 (0x00007f52a78c7000)
        libz.so.1 => /path/to/zlib/lib/libz.so.1 (0x00007f52a76b0000)
        libzstd.so.1.3.3 => /path/to/zstd/lib/libzstd.so.1.3.3 (0x00007f52a7443000)
...
 % objdump -x /path/to/build/blosc/libblosc_testing.so | grep zstd
  NEEDED               libzstd.so.1.3.3
  RPATH                /path/to/lz4/lib:/path/to/snappy/lib:/path/to/zlib/lib:/path/to/zstd/lib

With this patch, it works:

diff -u -r c-blosc-1.13.2.old/tests/CMakeLists.txt c-blosc-1.13.2/tests/CMakeLists.txt
--- c-blosc-1.13.2.old/tests/CMakeLists.txt     2018-01-25 00:46:54.523433391 +0000
+++ c-blosc-1.13.2/tests/CMakeLists.txt 2018-01-25 00:47:09.179575378 +0000
@@ -71,7 +71,7 @@
                         "${CMAKE_CURRENT_BINARY_DIR}/libblosc_testing.dll")
     endif()
 
-    target_link_libraries(${target} blosc_testing)
+    target_link_libraries(${target} blosc_shared_testing)
     add_dependencies(${target} blosc_shared_testing)
 
     # If there's a CSV file present for this test, read it to get the list

[FrancescAlted]

Ah, now that I read your subject better this should happen only when external libraries are in non-standard locations.

[leifwalsh]

Awesome, thanks for the fast turnaround!