@我怀疑你有问题：When I compile software that uses a configure script, the configure script thinks my system has all of the header files and libraries it is testing for. How do I get configure to work correctly?
The configure script is getting things wrong because the LLVM linker allows symbols to be undefined at link time (so that they can be resolved during JIT or translation to the C back end). That is why configure thinks your system "has everything."
To work around this, perform the following steps:
Make sure the CC and CXX environment variables contains the full path to the LLVM GCC front end.
Make sure that the regular C compiler is first in your PATH.
Add the string "-Wl,-native" to your CFLAGS environment variable.
This will allow the llvm-ld linker to create a native code executable instead of shell script that runs the JIT. Creating native code requires standard linkage, which in turn will allow the configure script to find out if code is not linking on your system because the feature isn't available on your system.