The configure script does not check liburcu's binary library
configure.ac only checks for liburcu function declarations in its installed headers using
If, for some reason, the system has the headers installed, but not the binary library, the
configure script succeeds, but the build fails later with obvious linking errors.
This situation happens if you set the various environment variables to build a 32-bit version of LTTng-tools (
LDFLAGS and so on) but only the 64-bit version of liburcu is installed. In this case, headers are found, for example in
configure succeeds, even if no 32-bit liburcu is installed.
It is okay to check the declarations, but
AC_CHECK_LIB() should also be used to check the existence of the chosen symbols in an installed binary liburcu.
configure.ac which seems to do the right thing.