Ubuntu - Curl development headers with SSL support - Passenger

Curl development headers with SSL support... not found

If I remove the unlink of the /tmp/passenger-curl-check.c and run the compile command directly I get IDN errors

gcc  -o '/tmp/passenger-curl-check' '/tmp/passenger-curl-check.c'  -lcurl 
/usr/lib/gcc/i486-linux-gnu/4.4.3/../../../../lib/libcurl.so: undefined reference to `idna_to_ascii_lz@LIBIDN_1.0'
/usr/lib/gcc/i486-linux-gnu/4.4.3/../../../../lib/libcurl.so: undefined reference to `tld_strerror@LIBIDN_1.0'
......


If I add -lidn it compiles fine

gcc  -o '/tmp/passenger-curl-check' '/tmp/passenger-curl-check.c'  -lcurl -lidn

--- curl config ----

> curl-config --libs
-lcurl
> curl-config --version
libcurl 7.19.7
> curl-config --features
SSL
IPv6
libz
IDN
NTLM
> curl-config --static-libs
/usr/lib/libcurl.a -lidn -lssl -lcrypto -llber -lldap -lrt -lgssapi_krb5 -lgssapi_krb5 -lssl -lcrypto -lz


I guess this is happening because --libs is not returning -lidn.