./configure CC='gcc -I/sw/include -L/sw/lib'
on make:

htsmodules.c: In function `getFunctionPtr':
htsmodules.c:160: warning: implicit declaration of function
`dlopen'
htsmodules.c:160: `RTLD_LAZY' undeclared (first use in this
function)
htsmodules.c:160: (Each undeclared identifier is reported
only once
htsmodules.c:160: for each function it appears in.)
htsmodules.c:160: warning: assignment makes pointer from
integer without a cast
htsmodules.c:163: warning: assignment makes pointer from
integer without a cast
htsmodules.c:167: warning: implicit declaration of function
`dlsym'
htsmodules.c:172: warning: implicit declaration of function
`dlclose'
htsmodules.c: At top level:
htsmodules.c:303: warning: no previous prototype for
`hts_is_available'
make[2]: *** [htsmodules.lo] Error 1
make[1]: *** [all-recursive] Error 1
make: *** [all] Error 2