PHP compile error: Warning: inter-library dependencies are not known to be supported.

I got a strange error when compiling PHP today:

*** Warning: inter-library dependencies are not known to be supported.
*** All declared inter-library dependencies are being dropped.
*** Warning: libtool could not satisfy all declared inter-library
*** dependencies of module libphp5. Therefore, libtool will create
*** a static module, that should work as long as the dlopening
*** application is linked with the -dlopen flag.
copying selected object files to avoid basename conflicts...


I recompiled PHP, with same options as last time, same version, but –with-curl added to the end of the options string. I got this error. So, the only change was the –with-curl-option. I tried without it, but no, same error. The result? libphp5.so was not compiled correctly, and PHP was not working…

The culprit turned out to be that libcurl and libxml was not compiled with different GCC versions, so they did not play well along. It was fixed by running an apt-get update && apt-get upgrade. However, I’m a bit baffled by the fact that PHP was not working even when compiling without CURL… I’m not sure why it did not work when compiling without curl, since no other changes were made to that box…

Oh, and to make it even better: PHP claims its not their problem… They could atleast give a bit more informative error message. But my suggestion is to ensure that all your libraries is up to date. The culprit in this case was libxml2 and curl, but it might be other libraries next time…