Do not export LD_LIBRARY_PATH globally

[mikhirev]

Hello!

In configure.ac paths to SSL libraries are added to LD_LIBRARY_PATH, that is exported immediately after that. In some cases this leads to breaking the toolchain, improper configuration and impossibility to compile.

In my particular case, I have custom openssl installation in non-standard prefix, and some other libraries, including zlib, there. After openssl is found and its path is added to LD_LIBRARY_PATH, some subsequent tests fail because ccache segfaults (it uses zlib to compress/decompress cached object files). ./configure finishes successfully, but compilation fails because of incorrect configuration.

As custom LD_LIBRARY_PATH is needed to execute tests only, it is better to set it when running tests, but not during configuration and build.

curl/libcurl version

Applicable to any version, including master.

operating system

Solaris 10 with gcc and ccache from opencsw, but also possible to reproduce on any Unix-like system.

[bagder]

If you look closer, you'll see that the configure scripts builds and executes a few of the tests. Those tests will fail if it can't link with the libs it has already detected it should use. Your bad ccache install is perhaps the first thing to fix here...

If you can make configure only use LD_LIBRARY_PATH in some more limited contexts and have that work, I'd welcome that.

[mikhirev]

Adding -L<PATH> to linker options (is't it already there?) and executing tests with env LD_LIBRARY_PATH="$MY_LD_LIBRARY_PATH" ./sometest will solve the problem with tests in configure. My ccache installation is fine, but it needs to use system libraries, but not those I want to link curl to…

[bagder]

-L is for link-time, so it doesn't help the run-time when executing tests.

I presume we can make a wrapper macro for AC_RUN_IFELSE that sets and unsets the LD_LIBRARY_PATH accordingly to make it only affect the actual running of the the tests...

[bagder]

Does my suggested change make it better for you?

[mikhirev]

@bagder thank you, it does exactly what I need. Test build in my environment passed successfully.

[bagder]

Lovely, thanks for the confirmation. I'll merge that...